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Re: H.323 QOS
by Roy, Radhika R, ALCOO 15 Aug '00

15 Aug '00

Hi, Skip: Yes, I agree with you. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Chip Sharp [mailto:chsharp@CISCO.COM] Sent: Tuesday, August 15, 2000 12:55 PM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS At 09:17 AM 8/15/00 -0400, Callaghan, Robert wrote: ...snip... >* My proposal is that the QoS is only negotiated with the original service >provider and that the QoS negotiation be performed between service >providers. Only the original service provider charges the user for the >service and this charge is split among the other service provider using a >process similar to that used by public telephone carriers today. All ISPs >do this today for basic service, so extending it to enhanced services is >reasonable. ...snip... Settlements in the ISP world are fairly byzantine and don't follow the model used by public telephone carriers today (possible exceptions are some of the arrangements for roaming and wholesale dial). Note the objections to draft Recommendation D.iii in SG3. What you suggest here would require a new business model, billing systems, OSS, etc. in the Service Providers(not to mention supporting the QOS in the first place). However, this is true for the alternatives proposed as well. :-) Chip ------------------------------------------------------------------- Chip Sharp Consulting Engineering Cisco Systems Reality - Love it or Change it. http://www.netaid.org ------------------------------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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Re: H.323 QOS
by Callaghan, Robert 15 Aug '00

15 Aug '00

Chip, I agree that the current situation is byzantine. However I think that SG3 has only two choices: 1) Pretend that nothing has changed, attempt to continue the past, and wonder why separations revenues are down. 2) Find a workable solution for the new world where voice is only funny data. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Chip Sharp [mailto:chsharp@cisco.com] Sent: Tuesday, August 15, 2000 12:55 PM To: Callaghan, Robert; ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS At 09:17 AM 8/15/00 -0400, Callaghan, Robert wrote: ...snip... >* My proposal is that the QoS is only negotiated with the original service >provider and that the QoS negotiation be performed between service >providers. Only the original service provider charges the user for the >service and this charge is split among the other service provider using a >process similar to that used by public telephone carriers today. All ISPs >do this today for basic service, so extending it to enhanced services is >reasonable. ...snip... Settlements in the ISP world are fairly byzantine and don't follow the model used by public telephone carriers today (possible exceptions are some of the arrangements for roaming and wholesale dial). Note the objections to draft Recommendation D.iii in SG3. What you suggest here would require a new business model, billing systems, OSS, etc. in the Service Providers(not to mention supporting the QOS in the first place). However, this is true for the alternatives proposed as well. :-) Chip ------------------------------------------------------------------- Chip Sharp Consulting Engineering Cisco Systems Reality - Love it or Change it. http://www.netaid.org ------------------------------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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Re: H.323 QOS
by Roy, Radhika R, ALCOO 15 Aug '00

15 Aug '00

Hi, Bob & Mike: As I mentioned in my earlier emails with respect to Bob questions: Bob wants that a service provider does not like to know whether it is a voice, video, or data call. It is a very simple requirement and one of the subsets that has been stated in Appendix of H.323 QOS Annex N. So, Bob will get his requirement satisfied. However, Appendix of H.323 QOS Annex N does more that. It can also provide differentiated QOS for each medium of H.323 within a given call, if needed. Let us separate two things: 1. What the H.323 QOS signaling messages are in the application layer and 2. What a service provider wants to do in the transport layer. Item 1 is our charter in H.323. We have to see whether item 2 falls into our charter in H.323 layer or it falls into the charter of network layer QOS or it is an implementation aspect of H.323 QOS over the transport layer. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Callaghan, Robert [mailto:Robert.Callaghan@ICN.SIEMENS.COM] Sent: Tuesday, August 15, 2000 9:18 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Mike, There is difference between the TIPHON work and what I think is needed: * TIPHON proposes a solution where the originator negotiates with all service providers along the path. This allows each service provider to change for the QoS individually. * My proposal is that the QoS is only negotiated with the original service provider and that the QoS negotiation be performed between service providers. Only the original service provider charges the user for the service and this charge is split among the other service provider using a process similar to that used by public telephone carriers today. All ISPs do this today for basic service, so extending it to enhanced services is reasonable. The other difference is in the information given to the service providers. I do no want the service providers to know that this is a voice call. Therefore, I do not want to use service provider gatekeepers. I only want the service providers to provide the requested QoS for any given connection without regards to the information content of the connection. You will be missed in Portland. It will be hard to have a comprehensive discussion of the topic with a major participant absent. This is true as the TIPHON leader, but also you personally. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Tuesday, August 15, 2000 8:16 AM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS Bob, I agree with your analysis. >Yes, our work is limited to H.323. This limits our ability to create a >general solution. On the other hand, if we consider H.323 QoS transport to >be a value added service, then the service providers can change a special >value added service charge for H.323 transport. A general solution is an >advantage to the H.323 solutions in that the QoS service charge is a general >change and not specific to H.323. (Sorry, for some people this is heresy.) This is very much the philosophy behind the TIPHON work. QoS will be charged for and there is a need for appropriate mechanisms to guarantee what is charged for, to monitor that what has been paid for has been delivered, and to account and bill. No one in TIPHON expects the Internet will be the medium for such value added services. Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Callaghan, Robert" <Robert.Callaghan(a)ICN.SIEMENS.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 7:16 PM Subject: Re: H.323 QOS Roy, Let me summaries my position, then we can talk next week. 1. I agree that H.323 is (mostly) transport independent. I also want the transport to be application independent. Another words, I do not want to tell the service provider that I am sending voice or any other media. I only want to tell the service provider that I need a given QoS for the data stream. 2. I agree that the QoS needs depend on the needs of a given data stream. It would be good if this can be specified. However, the means to specify this should be independent of the transported data (voice). 3. We definitely need a means to specify the end-to-end QoS on a demand basis. I would think that the originating service provider should be able to receive this and forward it to subsequent service providers based on the available and selected route. 4. I agree that the means used to specify the desired QoS should be independent of the transport layer. It should also be independent of the application. 5. Yes, our work is limited to H.323. This limits our ability to create a general solution. On the other hand, if we consider H.323 QoS transport to be a value added service, then the service providers can change a special value added service charge for H.323 transport. A general solution is an advantage to the H.323 solutions in that the QoS service charge is a general change and not specific to H.323. (Sorry, for some people this is heresy.) Maybe there is a balance between your method of specifying in detail the desired QoS and the fact that it is H.323 specific. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] Sent: Monday, August 14, 2000 11:29 AM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS Hi, Bob: I have provide my reply embedded in your email [RRR]. In addition, I am providing some general explanation. The fundamental problem is that the network layer QOS signaling schemes are different because these are transport dependent. In olden days, we have also made application specific to the particular transport mechanism. For example, H.320, H.321, etc. However, the application like H.323 has changed the landscape. It is transport independent although it can be sent over any transport network specific to meets its specific needs. For example, we change the abstraction of network address into IP, ATM, etc. as needed. So, this simple example shows how H.323 is transported in a specific network while the "network address" is the universal abstraction for both IP and ATM. If people want to solve having the service level agreement in a specific way without using any standards, it is their choice. In fact, many service providers are doing this in a proprietary manner toady. There is no common standard to express the QOS in a universal way that remains the same on end-to-end basis and there are so many translations in the network layer without having a common reference. As I explained above, if we want to make H.323 IP specific, we could do this as well. In this case, we do NOT need to make it transport independent. But the question is: Why did we make H.323 transport independent? We have discussed this a lot in the past while we have been developing Annex H.323 N, and have come to the same conclusion that we do need to make H.323 QOS transport independent so that it can be implemented for any network or a combination of networks or a combination of network layer QOS. It also bridges the fundamental gap that the application (audio codecs, video codecs, data) has its own intrinsic needs to express its QOS because it is the application whose needs to be satisfied no matter what the underlying transport network or networks may be. The beauty of H.245 is that it provides a negotiation capability on end-to-end basis and the same can also used for QOS (in fact, it is also used to day for RSVP, and ATM QOS in a monolithic network). The beauty of H.323 QOS Annex N is that it helps to implement all heterogeneous network layer QOS (RSVP, DiffServ, MPLS, ATM QOS, etc) in any combination that people may like to implement. Hope this will clarify your points further. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Callaghan, Robert [mailto:Robert.Callaghan@ICN.SIEMENS.COM] Sent: Monday, August 14, 2000 10:17 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Roy, I have two points: 1) For me, it is the responsibility of my service provider to provide the service agreed to in my service level agreement. This may require the existence of service level agreements between service providers; so be it. This should not be my problem. [RRR] Yes, that is why a service provider needs to have a common set of H.323 QOS that remains the same on end-to-end basis so that H.323 services can be provided transparently. My primary reference point is H.323 service providers, not transport network service providers. A transport network service provider may or may not need H.323 QOS. If a transport service provider may also use H.323 QOS a common basis for mapping among RSVP, DiffServ, MPLS, and ATM QOS at the network layer if they think that H.323 QOS is a good reference based on "standard." Please note that a service provider may have IP, ATM, and/or other networks to provide H.323 services. So, H.323 QOS will provide to have a common basis for translation in this heterogeneous networking environment. 2) The interface needed to obtain a given service level should be independent of the application, even when multi-service providers are involved on an end-to-end basis. That is, the interface should work for any application. Therefore there should not be any H.323 specific signaling required to obtain the requested QOS. [RRR] We are wearing the "Hat" of H.323. That is, we are NOT talking about only IP, ATM, etc. We are dealing with the H.323 application and the services related to H.323. So, H.323 QOS needs to be translated as needed in the transport layer. 3) The interface required to signal RSVP, DiffServ, MPLS, ATM QOS, etc. are all different. This is recognized today in H.245 in that RSVP and ATM QOS are handled differently. H.245 should be extended to handle all variant of QOS based on the needs of the individual specifications. [RRR] Yes, it is all different QOS in the network layer, but the H.323 application is "only one" and remains the same on end-to-end basis, and its QOS needs (what we call H.323 QOS end-to-end) is also the same and does not change not matter whether the network supports RSVP, DiffServ, MPLS, and/or ATM QOS. This is the problem that we have solved in H.323 QOS (you can see appendix of H.323 Annex N). If you go through appendix of H.323 Annex N, you can easily see how this problem has been solved. Please go through this annex N, ask me or others who worked for this annex specific questions if you have any. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] Sent: Monday, August 14, 2000 9:37 AM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS Hi, Bob: I agree completely agree with you. In fact, we are all trying to achieve the same goal. For example, H.323 does supports QOS today via H.245. You can easily see that RSVP and ATM QOS are supported using H.245. The beauty of this approach is that H.245 is still transport independent. All we have done here is: the abstraction of H.245 has been used to support the RSVP and ATM QOS to implement the network layer QOS. However, this is only good for the single network. For example, end-to-end RSVP or end-to-end ATM QOS. If there are multiple networks or if a single IP network implements RSVP in one domain, DiffServ in another domain, and MPLS in another domain, there is no transparent H.323 QOS signaling mechanism that is universal on end-to-end basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc transparently. In Appendix of H.323 Annex N, we have done the same. We have the abstraction of H.323 QOS in the application layer. We have shown how the H.323 QOS can be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. It also provides the backward compatibility with the existing H.323 standard. However, we have done only for the pre-call setup signaling part. We have not done the call setup part yet. In the call setup part, we will include H.245 in a similar way what H.323 is supporting RSVP and ATM QOS today in a monolithic network. I appreciate your email. Best regards, Radhika R. Roy AT&T > -----Original Message----- > From: Callaghan, Robert [SMTP:Robert.Callaghan@icn.siemens.com] > Sent: Monday, August 14, 2000 9:08 AM > To: Roy, Radhika R, ALCOO > Cc: 'Mailing list for parties associated with ITU-T Study Group 16' > Subject: RE: H.323 QOS > > Roy, > > In my view, the network, as a minimum, needs only provide transport. > H.323 > is an application using this transport and is not different from any other > application being transported. Any application may request a desired > quality of service that the network may grant based on policies, service > level agreements, and availability. Each data connection used by an > application may request a different QOS. Most likely H.323 is such an > application as needing an enhanced QOS. This simple case should work. > This > is all that is required. > > In addition to transport, the network may optionally provide other > additional services. These services may include application layer > routing. > These optional services should be configured and indicated independently > from the basic transport QOS. > > It is correct that H.323, as an application, is (mostly) transport > independent. However, the interface between the application and the > transport layer is not transport independent. The interface specification > used to request a given QOS is totally dependant on the standards body > that > specified the transport layer; and for this there has been little or no > coordination. > > Because transport QOS over IP is based on IETF specifications, it is > necessary that the interface used to request a given QOS conform to the > appropriate IETF specification. If such an interface specification is not > available, that input might be provided to the appropriate IETF body as to > the requirements. > > I can see the endpoints negotiating the desired QOS base on need, price, > and > other considerations. For me, this is the limit to the application layer > involvement in QOS negotiation. At this point, the application > negotiations > with the transport provider as to the desired and available QOS. It is up > to the transport provider to arrange for the end-to-end QOS. (Again, it > is > not necessary for the transport network to know that H.323 is involved in > the transported data. In fact it may be encrypted in order to mask the > presence of voice transport.) > > For me, this is simple. > > Bob > > ------------------------------------------------------------------ > Robert Callaghan > Siemens Enterprise Networks > Tel: +1.561.923.1756 Fax: +1.561.923.1403 > Email: Robert.Callaghan(a)ICN.Siemens.com > ------------------------------------------------------------------ > > -----Original Message----- > From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] > Sent: Friday, August 11, 2000 7:59 AM > To: ITU-SG16(a)mailbag.cps.intel.com > Subject: Re: H.323 QOS > > Hi, Mike: > > Let me try again. > > What is the reference point of H.323 QOS? Is it not H.323? If it is so, > what > do we mean by H.323? > > The answer is: Audio (different codecs), Video (different codecs), and > Data > (T.120 applications) that are used by H.323. > > What are the QOS/performance characteristics of audio, video, and data > from > the application point of view that is generated by audio codecs, video > codecs, and data (T.120) applications? > > These QOS/performance characteristics come from the SOURCE codecs and data > applications. Per transport independent H.323 specifications, an enduser > express their QOS/performance requirements on end-to-end basis purely from > application point of view irrespective of the transport network (e.g., IP, > ATM, etc.). > > Moreover, H.323 is meant for the packet network, not for any > circuit-switched network like PSTN or ISDN. > > Let us NOT go beyond this before we start debating transport layer QOS or > service provider requirements. These are NOT the concern of H.323. H.323 > is > the transport independent application. > > H.323v2/v3/v4 has also provided mechanisms how RSVP and ATM QOS can be > used > for H.323 audio, video, and data. So, H.323 QOS that will be defined in > H.323 Annex N MUST provide mapping for the backward compatibility. It is a > requirement that MUST be met per the norm of ITU-T. > > So, what is left for mapping? Mapping is simply a by-product of the above > requirement. Mapping is simply a table, nothing else. > > Did I miss anything? > > Best regards, > Radhika R. Roy > AT&T > > -----Original Message----- > From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] > Sent: Thursday, August 10, 2000 10:19 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: Re: H.323 QOS > > > Radhika, > > Thanks for the input which I welcome as I will unfortunately not be > present > at Portland. > > Let me ask a few questions and make a few comments hopefully with the > intent > of opening up the debate. > > 1. I am not sure I understand your concept of a mapping table between the > H.323 QOS and the transport layer QoS. My understanding is that QoS is on > three levels: > > a) that specified from a service point of view between the user and > service > provider (e.g PSTN quality, conference quality etc) This is the domain of > the speech experts and can be characterised by Listener Speech Quaklity > (MOS), end to end delay, and absolute category rating, R. > > b) application specific parameters, (e.g. equipment delays, codec choice > and performance, codec frame size, packetisation arrangements, jitter > buffer > design, overall packet loss etc.) Optimisation of all these will > determine > what can be delivered in a). > > c) transport parameters for a given choice of application parameters. > This > boils down only to three parameters as far as I cna see: tranport network > delay, packet delay variation in the transport network and packet loss in > the transport network. Again these parameters will determine the results > in > a) for a given choice of the parameters in b). These parameters are > generic > from the perspective of the transport network. i.e the transport network > does not need to know the details of the application. > > So the sequence of cause and effect and control is: > > a) User requests QoS class from service provider, > b) Service provider determines application specific parameters in > conjunction with users equipment and other service providers, > c) Service provider requests required delay, delay variation and packet > loss from network provider. > > I see no need for mapping here. The only QoS info flows within the > application are specific to the application and those between the > application (service provider) and the transport network are generic. i.e. > delay, jitter and packet loss. Have I missed something? > > 2. The issue of bit rate and media stream statistics I think need to be > decoupled from QoS. These are specified to enable optimisation of > resources > within the transport network. They have no QoS significance from an > application point of view. i.e the apllication does not care about the > media stream bit rate and statistics but the transport network provider > does > as it eats up his resource. They may be used for policy enforcement > however > in the transport network so they do need to be agreed between service > provider and network operator. i.e the network operator agrees to provide > a > given QoS level (delay, jitter, packet loss) provided the media properties > are within an agreed profile (bit rate, flow statistics). > > 3. The next point is how can the service provider know the statistics of > a > particular VBR stream? These can only be specified over a large number of > similar calls and will depend, for instance, on who is speaking, the > nature > of the speech interaction etc etc. They can only be measured not > calculated. The service provider is in no better position to measure > these > than the transport network operator and, in fact, where no gateways are > involved, may not be able to. On the other hand the class of signal would > have to be signalled to the network operator for him to be able to > distinguish which class a particular measurement belonged to. e.g > voice/speech/data, codec type, conference, multicast etc. So I see no > purpose in trying to exchange statistics between the service provider > (application) and transport operator. I think peak bit rate is all that > can > be meaningfully excanged. The specification of media class is however > perhaps worth exploring. > > 4. The controlled category has always puzzled me. I only see two > possibilities. Either the requested QoS level is guaranteed (on a > statistical basis e.g 95% of all connections over a specified period) or > not > guaranteed. Is your controlled category a way of saying guaranteed, not > to > 95% but to some lower figure? If you can't put a percentage on it then it > seems it is plain and simple not guaranteed. Anything that is not > guaranteed to some specified statistical level is best effort and you > can't > say anything more about it. So I only see two categories here. > > In summary, I think we need to do three things in Annex N. > > a) Figure out the QoS information to be exchanged within the Application > between service providers and end users. This will go in H.225.0 and > H.245. > > b) Figure out how we are going to signal QoS and media information between > the application (service providers) and transport domains (IP or ATM > networks etc). The info is basically delay, jitter, packet loss > requirements and peak bit rate. We need a protocol for this. > > c) we need to work out the interactions between the application QoS > signal > flows and the application/transport signal flows. I don't think we need > worry about how the transport network mechanisms assure the requested QoS > paramerters. RSVP/Intserv, Diffserv, MPLS, ATM, over provisioning are all > possibilities. > > Would welcome comments and views on the above. > > Mike > > > Mike Buckley > +44-1457-877718 (T) > +44-1457-877721 (F) > mikebuckley(a)44comms.com > > > ----- Original Message ----- > From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> > To: <ITU-SG16(a)MAILBAG.INTEL.COM> > Sent: Thursday, August 10, 2000 10:15 PM > Subject: H.323 QOS > > > Hi, Mike and All: > > It is time to discuss about H.323 QOS. > > I believe that we have an agreement as follows: > > · H.323 QOS MUST be backward compatible to support RSVP and ATM QOS as it > exists for H.323v2/v3/v4 > · Like H.323 spec, the application level H.323 QOS MUST be independent of > the transport layer QOS and should support all transport networks (e.g., > IP, > ATM) > · A mapping table between the H.323 QOS and the transport layer QOS (e.g., > IP QOS [DiffServ, RSVP, etc.], ATM QOS [CBR, rt-VBR, nrt-VBR, ABR, etc.]) > should be provided. > > From the H.323 multimedia application point of view, there are following > performance parameters can be used to characterize the traffic > characteristics: > > · Bitrate characteristics: Peak bit rate (PBR) or peak rate (PR), > Sustained > bit rate (SBR) or average rate (AR), minimum bit rate (MBR) or minimum > rate > (MR), and mean bust size (MBS) > · Delay and loss characteristics: end-to-end delay (EED) or delay, > end-to-end delay variation (EEDV) or delay variation (DV), and > bit-error-rate (BER) or (packet) loss rate (LR) > > We can now form a table with all parameters as follows: > > Table 1: H.323 Multimedia Application Performance Matrix > Audio (codecs)--- Video (codecs)--- Data > (T.120) > PBR/PR Yes/No/Value Yes/No/Value Yes/No/value > SBR/AR Yes/No/Value Yes/No/Value Yes/No/value > MBR/MR Yes/No/Value Yes/No/Value Yes/No/value > MBS Yes/No/Value Yes/No/Value Yes/No/value > EED/Delay Yes/No/Value Yes/No/Value Yes/No/value > EEDV/DV Yes/No/Value Yes/No/Value Yes/No/value > BER/LR Yes/No/Value Yes/No/Value Yes/No/value > > From the above table we will have the opportunity to choose each parameter > for each medium (audio, video, data) that makes sense from the > application's > and enduser's point of view. Again, these parameters can be specified as > follows: > > · Guaranteed: The value specified for each parameter MUST be guaranteed. > · Controlled: The value specified for each parameter MAY be satisfied as > far > as practicable (possibly with certain range), but definitely NOT > guaranteed. > · Best effort: No commitment will be made. > > Now each medium (e.g., audio, video, or data) will have different > categories > of performance matrix depending on its selection criteria and this can > also > be mapped to RSVP, ATM QOS, and others, if needed. > > Once we agree on this format, the next step is to create H.323 QOS > signaling > messages. > > This is my input for discussion in the upcoming Portland Q.13 meeting for > H.323 QOS. > > I like to see the comments from other members as well. > > Best regards, > Radhika R. Roy > AT&T > +1 732 420 1580 > rrroy(a)att.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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Re: H.323 QOS
by Roy, Radhika R, ALCOO 15 Aug '00

15 Aug '00

Hi, Mike: Just for information, H.245 does many things. As I indicated earlier, one of the most important things of H.245 is the opening and closing of the logical channels that binds the application layer's logical connection abstractions to all transport network connections (e.g., ATM, etc). So, this is the fundamental mission of H.245 to provide the continuity between the application layer and the lower layer in a transport independent way using the universal abstractions. These abstractions can be for anything that we can think of. Hope this helps. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Tuesday, August 15, 2000 8:22 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Hi Radhika, This use of H.245 as a bridging mechanism is where I have difficulties. The original intenmt behind H.245 was media control and negociation. Transport mechanisms should not be signalled in H.245 or elsewhere in the application. This is entirely the business of the transport network provider. Unfortunately I will not be present in Portland, however, I am happy to continue this productive dialogue on the list with a view to providing a new draft in the next few weeks. Regards, Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 7:29 PM Subject: Re: H.323 QOS Hi, Mike: I guess that we have agreement on the fundamental basis. However, I have problems when you translate this in signaling terms. As I have explained earlier that we are following the exiting framework of H.323 which is the application layer, and H.323 is transported over one or different transport networks. H.323 uses H.245 as a common mechanism that helps to transports the abstraction of H.323 application signaling messages over any networks (e.g., IP, ATM, etc). You may look to the H.245 spec very carefully instead of making any generalized statement. H.245 provides the bridging between the application layer and transport layer mechanism. For example, H.245's OLC abstraction is the link for ATM network layer logical connection as well as for other transport networks. In the same token, H.323 QOS abstraction may also provide link to the lower transport layer QOS signaling mechanisms (e.g., RSVP, DiffServ, MPLS, ATM QOS, etc), if needed. H.323 DOES support RSVP and ATM QOS now. Please also see my reply embedded in you email [RRR]. Again, I would suggest to bring contributions explaining the solution and we will go from there. In absence of your contributions, I would suggest to provide comments on Appendix of H.323 QOS Annex N. We can then answer your questions step by step. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Monday, August 14, 2000 12:56 PM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Radhika, >However, this is only good for the single network. For example, >end-to-end RSVP or end-to-end ATM QOS. >If there are multiple networks or if a single IP network implements RSVP in >one domain, DiffServ in another domain, and MPLS in another domain, there is >no transparent H.323 QOS signaling mechanism that is universal on end-to-end >basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc >transparently This is the nub of the problem and I am afraid why this approach is flawed. [RRR] I am NOT afraid of anything. Rather we are solving all problems including the above as well. No one should be afraid of anything. The only thing that I can suggest is to bring contributions. We will go from there. Please remember that H.323 QOS supports RSVP and ATM QOS and we MUST provide backward compatibility. We will be waiting to see contributions from you to prove your points whether things are flawed or not. Please read Appnedix of H.323 QOS Annex N very carefully along with exiting H.323 and H.245 standard how they support H.323 QOS for RSVP and ATM QOS. >We have shown how the H.323 QOS can >be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. This mapping must be done within the transport plane not by the application. All the application needs to specify are the entries in your Table 1. i.e delay, jitter. packet loss and peak bit rate (the latter parameter for policy enforcement and resource reservation). [RRR] Please see my generalized clarification how H.245 provides translation between H.323 signaling schemes over the lower layer transport networks (e.g., IP, ATM, etc). The mechanism already exists in H.323 and this is the beauty of the transport independent H.323 application. Now there are two separate things: one is what the calling side of the application demands and what the called side of the application agrees on. This is called negotiation capability (e.g., choosing a particular type codec that has a certain bandwidth, jitter, and other requirements). How the choosing criteria is determined, the H.323 application is NOT aware of those things. It may depend on many criteria (e.g., policy, bandwidth, type of network [e.g., IP, ATM], pricing, security, personal preferences, etc.), but H.323 is not involved. These are separate issues and we are NOT addressing at the H.323 layer. I am still not clkear how you propose to signal these parameters to the transport plane. [RRR] It is NOT new in H.323, and this mechanism already exits. Please see the support of RSVP and ATM QOS in H.323/H.245 spec. We are not inventing anything NEW here. Then, if you read Appendix of H.323 QOS Annex N very carefully, you will find how it happening (whether you call it as transport plane or something else, it does not matter). I think we are getting loser to a common understanding. Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 2:37 PM Subject: Re: H.323 QOS Hi, Bob: I agree completely agree with you. In fact, we are all trying to achieve the same goal. For example, H.323 does supports QOS today via H.245. You can easily see that RSVP and ATM QOS are supported using H.245. The beauty of this approach is that H.245 is still transport independent. All we have done here is: the abstraction of H.245 has been used to support the RSVP and ATM QOS to implement the network layer QOS. However, this is only good for the single network. For example, end-to-end RSVP or end-to-end ATM QOS. If there are multiple networks or if a single IP network implements RSVP in one domain, DiffServ in another domain, and MPLS in another domain, there is no transparent H.323 QOS signaling mechanism that is universal on end-to-end basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc transparently. In Appendix of H.323 Annex N, we have done the same. We have the abstraction of H.323 QOS in the application layer. We have shown how the H.323 QOS can be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. It also provides the backward compatibility with the existing H.323 standard. However, we have done only for the pre-call setup signaling part. We have not done the call setup part yet. In the call setup part, we will include H.245 in a similar way what H.323 is supporting RSVP and ATM QOS today in a monolithic network. I appreciate your email. Best regards, Radhika R. Roy AT&T > -----Original Message----- > From: Callaghan, Robert [SMTP:Robert.Callaghan@icn.siemens.com] > Sent: Monday, August 14, 2000 9:08 AM > To: Roy, Radhika R, ALCOO > Cc: 'Mailing list for parties associated with ITU-T Study Group 16' > Subject: RE: H.323 QOS > > Roy, > > In my view, the network, as a minimum, needs only provide transport. > H.323 > is an application using this transport and is not different from any other > application being transported. Any application may request a desired > quality of service that the network may grant based on policies, service > level agreements, and availability. Each data connection used by an > application may request a different QOS. Most likely H.323 is such an > application as needing an enhanced QOS. This simple case should work. > This > is all that is required. > > In addition to transport, the network may optionally provide other > additional services. These services may include application layer > routing. > These optional services should be configured and indicated independently > from the basic transport QOS. > > It is correct that H.323, as an application, is (mostly) transport > independent. However, the interface between the application and the > transport layer is not transport independent. The interface specification > used to request a given QOS is totally dependant on the standards body > that > specified the transport layer; and for this there has been little or no > coordination. > > Because transport QOS over IP is based on IETF specifications, it is > necessary that the interface used to request a given QOS conform to the > appropriate IETF specification. If such an interface specification is not > available, that input might be provided to the appropriate IETF body as to > the requirements. > > I can see the endpoints negotiating the desired QOS base on need, price, > and > other considerations. For me, this is the limit to the application layer > involvement in QOS negotiation. At this point, the application > negotiations > with the transport provider as to the desired and available QOS. It is up > to the transport provider to arrange for the end-to-end QOS. (Again, it > is > not necessary for the transport network to know that H.323 is involved in > the transported data. In fact it may be encrypted in order to mask the > presence of voice transport.) > > For me, this is simple. > > Bob > > ------------------------------------------------------------------ > Robert Callaghan > Siemens Enterprise Networks > Tel: +1.561.923.1756 Fax: +1.561.923.1403 > Email: Robert.Callaghan(a)ICN.Siemens.com > ------------------------------------------------------------------ > > -----Original Message----- > From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] > Sent: Friday, August 11, 2000 7:59 AM > To: ITU-SG16(a)mailbag.cps.intel.com > Subject: Re: H.323 QOS > > Hi, Mike: > > Let me try again. > > What is the reference point of H.323 QOS? Is it not H.323? If it is so, > what > do we mean by H.323? > > The answer is: Audio (different codecs), Video (different codecs), and > Data > (T.120 applications) that are used by H.323. > > What are the QOS/performance characteristics of audio, video, and data > from > the application point of view that is generated by audio codecs, video > codecs, and data (T.120) applications? > > These QOS/performance characteristics come from the SOURCE codecs and data > applications. Per transport independent H.323 specifications, an enduser > express their QOS/performance requirements on end-to-end basis purely from > application point of view irrespective of the transport network (e.g., IP, > ATM, etc.). > > Moreover, H.323 is meant for the packet network, not for any > circuit-switched network like PSTN or ISDN. > > Let us NOT go beyond this before we start debating transport layer QOS or > service provider requirements. These are NOT the concern of H.323. H.323 > is > the transport independent application. > > H.323v2/v3/v4 has also provided mechanisms how RSVP and ATM QOS can be > used > for H.323 audio, video, and data. So, H.323 QOS that will be defined in > H.323 Annex N MUST provide mapping for the backward compatibility. It is a > requirement that MUST be met per the norm of ITU-T. > > So, what is left for mapping? Mapping is simply a by-product of the above > requirement. Mapping is simply a table, nothing else. > > Did I miss anything? > > Best regards, > Radhika R. Roy > AT&T > > -----Original Message----- > From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] > Sent: Thursday, August 10, 2000 10:19 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: Re: H.323 QOS > > > Radhika, > > Thanks for the input which I welcome as I will unfortunately not be > present > at Portland. > > Let me ask a few questions and make a few comments hopefully with the > intent > of opening up the debate. > > 1. I am not sure I understand your concept of a mapping table between the > H.323 QOS and the transport layer QoS. My understanding is that QoS is on > three levels: > > a) that specified from a service point of view between the user and > service > provider (e.g PSTN quality, conference quality etc) This is the domain of > the speech experts and can be characterised by Listener Speech Quaklity > (MOS), end to end delay, and absolute category rating, R. > > b) application specific parameters, (e.g. equipment delays, codec choice > and performance, codec frame size, packetisation arrangements, jitter > buffer > design, overall packet loss etc.) Optimisation of all these will > determine > what can be delivered in a). > > c) transport parameters for a given choice of application parameters. > This > boils down only to three parameters as far as I cna see: tranport network > delay, packet delay variation in the transport network and packet loss in > the transport network. Again these parameters will determine the results > in > a) for a given choice of the parameters in b). These parameters are > generic > from the perspective of the transport network. i.e the transport network > does not need to know the details of the application. > > So the sequence of cause and effect and control is: > > a) User requests QoS class from service provider, > b) Service provider determines application specific parameters in > conjunction with users equipment and other service providers, > c) Service provider requests required delay, delay variation and packet > loss from network provider. > > I see no need for mapping here. The only QoS info flows within the > application are specific to the application and those between the > application (service provider) and the transport network are generic. i.e. > delay, jitter and packet loss. Have I missed something? > > 2. The issue of bit rate and media stream statistics I think need to be > decoupled from QoS. These are specified to enable optimisation of > resources > within the transport network. They have no QoS significance from an > application point of view. i.e the apllication does not care about the > media stream bit rate and statistics but the transport network provider > does > as it eats up his resource. They may be used for policy enforcement > however > in the transport network so they do need to be agreed between service > provider and network operator. i.e the network operator agrees to provide > a > given QoS level (delay, jitter, packet loss) provided the media properties > are within an agreed profile (bit rate, flow statistics). > > 3. The next point is how can the service provider know the statistics of > a > particular VBR stream? These can only be specified over a large number of > similar calls and will depend, for instance, on who is speaking, the > nature > of the speech interaction etc etc. They can only be measured not > calculated. The service provider is in no better position to measure > these > than the transport network operator and, in fact, where no gateways are > involved, may not be able to. On the other hand the class of signal would > have to be signalled to the network operator for him to be able to > distinguish which class a particular measurement belonged to. e.g > voice/speech/data, codec type, conference, multicast etc. So I see no > purpose in trying to exchange statistics between the service provider > (application) and transport operator. I think peak bit rate is all that > can > be meaningfully excanged. The specification of media class is however > perhaps worth exploring. > > 4. The controlled category has always puzzled me. I only see two > possibilities. Either the requested QoS level is guaranteed (on a > statistical basis e.g 95% of all connections over a specified period) or > not > guaranteed. Is your controlled category a way of saying guaranteed, not > to > 95% but to some lower figure? If you can't put a percentage on it then it > seems it is plain and simple not guaranteed. Anything that is not > guaranteed to some specified statistical level is best effort and you > can't > say anything more about it. So I only see two categories here. > > In summary, I think we need to do three things in Annex N. > > a) Figure out the QoS information to be exchanged within the Application > between service providers and end users. This will go in H.225.0 and > H.245. > > b) Figure out how we are going to signal QoS and media information between > the application (service providers) and transport domains (IP or ATM > networks etc). The info is basically delay, jitter, packet loss > requirements and peak bit rate. We need a protocol for this. > > c) we need to work out the interactions between the application QoS > signal > flows and the application/transport signal flows. I don't think we need > worry about how the transport network mechanisms assure the requested QoS > paramerters. RSVP/Intserv, Diffserv, MPLS, ATM, over provisioning are all > possibilities. > > Would welcome comments and views on the above. > > Mike > > > Mike Buckley > +44-1457-877718 (T) > +44-1457-877721 (F) > mikebuckley(a)44comms.com > > > ----- Original Message ----- > From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> > To: <ITU-SG16(a)MAILBAG.INTEL.COM> > Sent: Thursday, August 10, 2000 10:15 PM > Subject: H.323 QOS > > > Hi, Mike and All: > > It is time to discuss about H.323 QOS. > > I believe that we have an agreement as follows: > > · H.323 QOS MUST be backward compatible to support RSVP and ATM QOS as it > exists for H.323v2/v3/v4 > · Like H.323 spec, the application level H.323 QOS MUST be independent of > the transport layer QOS and should support all transport networks (e.g., > IP, > ATM) > · A mapping table between the H.323 QOS and the transport layer QOS (e.g., > IP QOS [DiffServ, RSVP, etc.], ATM QOS [CBR, rt-VBR, nrt-VBR, ABR, etc.]) > should be provided. > > From the H.323 multimedia application point of view, there are following > performance parameters can be used to characterize the traffic > characteristics: > > · Bitrate characteristics: Peak bit rate (PBR) or peak rate (PR), > Sustained > bit rate (SBR) or average rate (AR), minimum bit rate (MBR) or minimum > rate > (MR), and mean bust size (MBS) > · Delay and loss characteristics: end-to-end delay (EED) or delay, > end-to-end delay variation (EEDV) or delay variation (DV), and > bit-error-rate (BER) or (packet) loss rate (LR) > > We can now form a table with all parameters as follows: > > Table 1: H.323 Multimedia Application Performance Matrix > Audio (codecs)--- Video (codecs)--- Data > (T.120) > PBR/PR Yes/No/Value Yes/No/Value Yes/No/value > SBR/AR Yes/No/Value Yes/No/Value Yes/No/value > MBR/MR Yes/No/Value Yes/No/Value Yes/No/value > MBS Yes/No/Value Yes/No/Value Yes/No/value > EED/Delay Yes/No/Value Yes/No/Value Yes/No/value > EEDV/DV Yes/No/Value Yes/No/Value Yes/No/value > BER/LR Yes/No/Value Yes/No/Value Yes/No/value > > From the above table we will have the opportunity to choose each parameter > for each medium (audio, video, data) that makes sense from the > application's > and enduser's point of view. Again, these parameters can be specified as > follows: > > · Guaranteed: The value specified for each parameter MUST be guaranteed. > · Controlled: The value specified for each parameter MAY be satisfied as > far > as practicable (possibly with certain range), but definitely NOT > guaranteed. > · Best effort: No commitment will be made. > > Now each medium (e.g., audio, video, or data) will have different > categories > of performance matrix depending on its selection criteria and this can > also > be mapped to RSVP, ATM QOS, and others, if needed. > > Once we agree on this format, the next step is to create H.323 QOS > signaling > messages. > > This is my input for discussion in the upcoming Portland Q.13 meeting for > H.323 QOS. > > I like to see the comments from other members as well. > > Best regards, > Radhika R. Roy > AT&T > +1 732 420 1580 > rrroy(a)att.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

2 1

URL to support Number Portability [was: draft-yu-tel-url-00.txt]
by Orit Levin 15 Aug '00

15 Aug '00

James! After reviewing your draft, below are my comments. As in regards to H.323, H.323 doesn't currently have an explicit notion of two different fields carrying the exact meaning of "current destination" and "the final recipient", using SIP language. On the other hand, the definition of H.323 URL potentially allows for cascading of URLs of different kinds. This concept appear in the last draft of "Annex O" to be discussed next week. Therefore, tel url can be placed in the "user" part of H.323 URL. Since, in your proposal, the original "final recipient" information (i.e. the phone number itself) is preserved in the tel url after the NPDB deep is performed, I don't see a technical problem for using the proposed algorithm within H.323. I will bring your work to the attention of H.323 community next week, including the H.323 mobility WG. My question (and that of the H.323 community) would be: what level of consensus does the approach, presented in your draft, currently have within SIP and IPTEL working groups? Orit Levin RADVision Inc. 575 Corporate Drive Suite 420 Mahwah, NJ 07430 Tel: 1 201 529 4300 (230) Fax: 1 201 529 3516 www.radvision.com orit(a)radvision.com -----Original Message----- From: James Yu <james.yu(a)neustar.com> To: 'Orit Levin' <orit(a)radvision.com>; IPTEL WG <iptel(a)lists.bell-labs.com> Date: Monday, August 14, 2000 1:24 PM Subject: RE: [IPTEL] A draft of H323-URL to be presented during the IPTEL session >Orit, > >Please review the attached draft-yu-tel-url-00.txt, titled "Extensions to >the tel and fax URL to support Number Portability." It is intended for the >SIP to carry number portability (NP) information in the Request URI field. >It may be carried by H.225.0 directly or may be mapped to the proposed H.323 >URL to support NP in H.323. > >There has not been lots of discussion on this I-D. Comments from you and >others are welcome. > >James > > > >-----Original Message----- >From: Orit Levin [mailto:orit@radvision.com] >Sent: Monday, July 31, 2000 9:05 PM >To: IPTEL WG >Subject: [IPTEL] A draft of H323-URL to be presented during the IPTEL >session > > >Hello! >I have submitted the attached draft 3 weeks ago. >Unfortunately, the document doesn't appear on the IETF Drafts site. >Since this topic is going to be presented during the IPTEL session on >Thursday morning, I am attaching the draft for you review. >Best Regards, >Orit Levin >RADVision Inc. >575 Corporate Drive Suite 420 >Mahwah, NJ 07430 >Tel: 1 201 529 4300 (230) >Fax: 1 201 529 3516 >www.radvision.com <http://www.radvision.com> >orit(a)radvision.com <mailto:orit@radvision.com> >-----Original Message----- >From: Orit Levin < orit(a)radvision.com <mailto:orit@radvision.com> > >To: internet-drafts(a)ietf.org <mailto:internet-drafts@ietf.org> < >internet-drafts(a)ietf.org <mailto:internet-drafts@ietf.org> > >Date: Tuesday, July 11, 2000 1:59 AM >Subject: Request for Draft Submission > > >Hello! >I would like to submit the attached paper as the first drafts to become an >Informational RFC. >Thank you, >Orit Levin >RADVision Inc. >575 Corporate Drive Suite 420 >Mahwah, NJ 07430 >Tel: 1 201 529 4300 (230) >Fax: 1 201 529 3516 >www.radvision.com <http://www.radvision.com> >orit(a)radvision.com <mailto:orit@radvision.com> > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 0

Re: H.323 QOS
by Callaghan, Robert 15 Aug '00

15 Aug '00

Mike, There is difference between the TIPHON work and what I think is needed: * TIPHON proposes a solution where the originator negotiates with all service providers along the path. This allows each service provider to change for the QoS individually. * My proposal is that the QoS is only negotiated with the original service provider and that the QoS negotiation be performed between service providers. Only the original service provider charges the user for the service and this charge is split among the other service provider using a process similar to that used by public telephone carriers today. All ISPs do this today for basic service, so extending it to enhanced services is reasonable. The other difference is in the information given to the service providers. I do no want the service providers to know that this is a voice call. Therefore, I do not want to use service provider gatekeepers. I only want the service providers to provide the requested QoS for any given connection without regards to the information content of the connection. You will be missed in Portland. It will be hard to have a comprehensive discussion of the topic with a major participant absent. This is true as the TIPHON leader, but also you personally. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Tuesday, August 15, 2000 8:16 AM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS Bob, I agree with your analysis. >Yes, our work is limited to H.323. This limits our ability to create a >general solution. On the other hand, if we consider H.323 QoS transport to >be a value added service, then the service providers can change a special >value added service charge for H.323 transport. A general solution is an >advantage to the H.323 solutions in that the QoS service charge is a general >change and not specific to H.323. (Sorry, for some people this is heresy.) This is very much the philosophy behind the TIPHON work. QoS will be charged for and there is a need for appropriate mechanisms to guarantee what is charged for, to monitor that what has been paid for has been delivered, and to account and bill. No one in TIPHON expects the Internet will be the medium for such value added services. Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Callaghan, Robert" <Robert.Callaghan(a)ICN.SIEMENS.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 7:16 PM Subject: Re: H.323 QOS Roy, Let me summaries my position, then we can talk next week. 1. I agree that H.323 is (mostly) transport independent. I also want the transport to be application independent. Another words, I do not want to tell the service provider that I am sending voice or any other media. I only want to tell the service provider that I need a given QoS for the data stream. 2. I agree that the QoS needs depend on the needs of a given data stream. It would be good if this can be specified. However, the means to specify this should be independent of the transported data (voice). 3. We definitely need a means to specify the end-to-end QoS on a demand basis. I would think that the originating service provider should be able to receive this and forward it to subsequent service providers based on the available and selected route. 4. I agree that the means used to specify the desired QoS should be independent of the transport layer. It should also be independent of the application. 5. Yes, our work is limited to H.323. This limits our ability to create a general solution. On the other hand, if we consider H.323 QoS transport to be a value added service, then the service providers can change a special value added service charge for H.323 transport. A general solution is an advantage to the H.323 solutions in that the QoS service charge is a general change and not specific to H.323. (Sorry, for some people this is heresy.) Maybe there is a balance between your method of specifying in detail the desired QoS and the fact that it is H.323 specific. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] Sent: Monday, August 14, 2000 11:29 AM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS Hi, Bob: I have provide my reply embedded in your email [RRR]. In addition, I am providing some general explanation. The fundamental problem is that the network layer QOS signaling schemes are different because these are transport dependent. In olden days, we have also made application specific to the particular transport mechanism. For example, H.320, H.321, etc. However, the application like H.323 has changed the landscape. It is transport independent although it can be sent over any transport network specific to meets its specific needs. For example, we change the abstraction of network address into IP, ATM, etc. as needed. So, this simple example shows how H.323 is transported in a specific network while the "network address" is the universal abstraction for both IP and ATM. If people want to solve having the service level agreement in a specific way without using any standards, it is their choice. In fact, many service providers are doing this in a proprietary manner toady. There is no common standard to express the QOS in a universal way that remains the same on end-to-end basis and there are so many translations in the network layer without having a common reference. As I explained above, if we want to make H.323 IP specific, we could do this as well. In this case, we do NOT need to make it transport independent. But the question is: Why did we make H.323 transport independent? We have discussed this a lot in the past while we have been developing Annex H.323 N, and have come to the same conclusion that we do need to make H.323 QOS transport independent so that it can be implemented for any network or a combination of networks or a combination of network layer QOS. It also bridges the fundamental gap that the application (audio codecs, video codecs, data) has its own intrinsic needs to express its QOS because it is the application whose needs to be satisfied no matter what the underlying transport network or networks may be. The beauty of H.245 is that it provides a negotiation capability on end-to-end basis and the same can also used for QOS (in fact, it is also used to day for RSVP, and ATM QOS in a monolithic network). The beauty of H.323 QOS Annex N is that it helps to implement all heterogeneous network layer QOS (RSVP, DiffServ, MPLS, ATM QOS, etc) in any combination that people may like to implement. Hope this will clarify your points further. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Callaghan, Robert [mailto:Robert.Callaghan@ICN.SIEMENS.COM] Sent: Monday, August 14, 2000 10:17 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Roy, I have two points: 1) For me, it is the responsibility of my service provider to provide the service agreed to in my service level agreement. This may require the existence of service level agreements between service providers; so be it. This should not be my problem. [RRR] Yes, that is why a service provider needs to have a common set of H.323 QOS that remains the same on end-to-end basis so that H.323 services can be provided transparently. My primary reference point is H.323 service providers, not transport network service providers. A transport network service provider may or may not need H.323 QOS. If a transport service provider may also use H.323 QOS a common basis for mapping among RSVP, DiffServ, MPLS, and ATM QOS at the network layer if they think that H.323 QOS is a good reference based on "standard." Please note that a service provider may have IP, ATM, and/or other networks to provide H.323 services. So, H.323 QOS will provide to have a common basis for translation in this heterogeneous networking environment. 2) The interface needed to obtain a given service level should be independent of the application, even when multi-service providers are involved on an end-to-end basis. That is, the interface should work for any application. Therefore there should not be any H.323 specific signaling required to obtain the requested QOS. [RRR] We are wearing the "Hat" of H.323. That is, we are NOT talking about only IP, ATM, etc. We are dealing with the H.323 application and the services related to H.323. So, H.323 QOS needs to be translated as needed in the transport layer. 3) The interface required to signal RSVP, DiffServ, MPLS, ATM QOS, etc. are all different. This is recognized today in H.245 in that RSVP and ATM QOS are handled differently. H.245 should be extended to handle all variant of QOS based on the needs of the individual specifications. [RRR] Yes, it is all different QOS in the network layer, but the H.323 application is "only one" and remains the same on end-to-end basis, and its QOS needs (what we call H.323 QOS end-to-end) is also the same and does not change not matter whether the network supports RSVP, DiffServ, MPLS, and/or ATM QOS. This is the problem that we have solved in H.323 QOS (you can see appendix of H.323 Annex N). If you go through appendix of H.323 Annex N, you can easily see how this problem has been solved. Please go through this annex N, ask me or others who worked for this annex specific questions if you have any. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] Sent: Monday, August 14, 2000 9:37 AM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS Hi, Bob: I agree completely agree with you. In fact, we are all trying to achieve the same goal. For example, H.323 does supports QOS today via H.245. You can easily see that RSVP and ATM QOS are supported using H.245. The beauty of this approach is that H.245 is still transport independent. All we have done here is: the abstraction of H.245 has been used to support the RSVP and ATM QOS to implement the network layer QOS. However, this is only good for the single network. For example, end-to-end RSVP or end-to-end ATM QOS. If there are multiple networks or if a single IP network implements RSVP in one domain, DiffServ in another domain, and MPLS in another domain, there is no transparent H.323 QOS signaling mechanism that is universal on end-to-end basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc transparently. In Appendix of H.323 Annex N, we have done the same. We have the abstraction of H.323 QOS in the application layer. We have shown how the H.323 QOS can be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. It also provides the backward compatibility with the existing H.323 standard. However, we have done only for the pre-call setup signaling part. We have not done the call setup part yet. In the call setup part, we will include H.245 in a similar way what H.323 is supporting RSVP and ATM QOS today in a monolithic network. I appreciate your email. Best regards, Radhika R. Roy AT&T > -----Original Message----- > From: Callaghan, Robert [SMTP:Robert.Callaghan@icn.siemens.com] > Sent: Monday, August 14, 2000 9:08 AM > To: Roy, Radhika R, ALCOO > Cc: 'Mailing list for parties associated with ITU-T Study Group 16' > Subject: RE: H.323 QOS > > Roy, > > In my view, the network, as a minimum, needs only provide transport. > H.323 > is an application using this transport and is not different from any other > application being transported. Any application may request a desired > quality of service that the network may grant based on policies, service > level agreements, and availability. Each data connection used by an > application may request a different QOS. Most likely H.323 is such an > application as needing an enhanced QOS. This simple case should work. > This > is all that is required. > > In addition to transport, the network may optionally provide other > additional services. These services may include application layer > routing. > These optional services should be configured and indicated independently > from the basic transport QOS. > > It is correct that H.323, as an application, is (mostly) transport > independent. However, the interface between the application and the > transport layer is not transport independent. The interface specification > used to request a given QOS is totally dependant on the standards body > that > specified the transport layer; and for this there has been little or no > coordination. > > Because transport QOS over IP is based on IETF specifications, it is > necessary that the interface used to request a given QOS conform to the > appropriate IETF specification. If such an interface specification is not > available, that input might be provided to the appropriate IETF body as to > the requirements. > > I can see the endpoints negotiating the desired QOS base on need, price, > and > other considerations. For me, this is the limit to the application layer > involvement in QOS negotiation. At this point, the application > negotiations > with the transport provider as to the desired and available QOS. It is up > to the transport provider to arrange for the end-to-end QOS. (Again, it > is > not necessary for the transport network to know that H.323 is involved in > the transported data. In fact it may be encrypted in order to mask the > presence of voice transport.) > > For me, this is simple. > > Bob > > ------------------------------------------------------------------ > Robert Callaghan > Siemens Enterprise Networks > Tel: +1.561.923.1756 Fax: +1.561.923.1403 > Email: Robert.Callaghan(a)ICN.Siemens.com > ------------------------------------------------------------------ > > -----Original Message----- > From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] > Sent: Friday, August 11, 2000 7:59 AM > To: ITU-SG16(a)mailbag.cps.intel.com > Subject: Re: H.323 QOS > > Hi, Mike: > > Let me try again. > > What is the reference point of H.323 QOS? Is it not H.323? If it is so, > what > do we mean by H.323? > > The answer is: Audio (different codecs), Video (different codecs), and > Data > (T.120 applications) that are used by H.323. > > What are the QOS/performance characteristics of audio, video, and data > from > the application point of view that is generated by audio codecs, video > codecs, and data (T.120) applications? > > These QOS/performance characteristics come from the SOURCE codecs and data > applications. Per transport independent H.323 specifications, an enduser > express their QOS/performance requirements on end-to-end basis purely from > application point of view irrespective of the transport network (e.g., IP, > ATM, etc.). > > Moreover, H.323 is meant for the packet network, not for any > circuit-switched network like PSTN or ISDN. > > Let us NOT go beyond this before we start debating transport layer QOS or > service provider requirements. These are NOT the concern of H.323. H.323 > is > the transport independent application. > > H.323v2/v3/v4 has also provided mechanisms how RSVP and ATM QOS can be > used > for H.323 audio, video, and data. So, H.323 QOS that will be defined in > H.323 Annex N MUST provide mapping for the backward compatibility. It is a > requirement that MUST be met per the norm of ITU-T. > > So, what is left for mapping? Mapping is simply a by-product of the above > requirement. Mapping is simply a table, nothing else. > > Did I miss anything? > > Best regards, > Radhika R. Roy > AT&T > > -----Original Message----- > From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] > Sent: Thursday, August 10, 2000 10:19 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: Re: H.323 QOS > > > Radhika, > > Thanks for the input which I welcome as I will unfortunately not be > present > at Portland. > > Let me ask a few questions and make a few comments hopefully with the > intent > of opening up the debate. > > 1. I am not sure I understand your concept of a mapping table between the > H.323 QOS and the transport layer QoS. My understanding is that QoS is on > three levels: > > a) that specified from a service point of view between the user and > service > provider (e.g PSTN quality, conference quality etc) This is the domain of > the speech experts and can be characterised by Listener Speech Quaklity > (MOS), end to end delay, and absolute category rating, R. > > b) application specific parameters, (e.g. equipment delays, codec choice > and performance, codec frame size, packetisation arrangements, jitter > buffer > design, overall packet loss etc.) Optimisation of all these will > determine > what can be delivered in a). > > c) transport parameters for a given choice of application parameters. > This > boils down only to three parameters as far as I cna see: tranport network > delay, packet delay variation in the transport network and packet loss in > the transport network. Again these parameters will determine the results > in > a) for a given choice of the parameters in b). These parameters are > generic > from the perspective of the transport network. i.e the transport network > does not need to know the details of the application. > > So the sequence of cause and effect and control is: > > a) User requests QoS class from service provider, > b) Service provider determines application specific parameters in > conjunction with users equipment and other service providers, > c) Service provider requests required delay, delay variation and packet > loss from network provider. > > I see no need for mapping here. The only QoS info flows within the > application are specific to the application and those between the > application (service provider) and the transport network are generic. i.e. > delay, jitter and packet loss. Have I missed something? > > 2. The issue of bit rate and media stream statistics I think need to be > decoupled from QoS. These are specified to enable optimisation of > resources > within the transport network. They have no QoS significance from an > application point of view. i.e the apllication does not care about the > media stream bit rate and statistics but the transport network provider > does > as it eats up his resource. They may be used for policy enforcement > however > in the transport network so they do need to be agreed between service > provider and network operator. i.e the network operator agrees to provide > a > given QoS level (delay, jitter, packet loss) provided the media properties > are within an agreed profile (bit rate, flow statistics). > > 3. The next point is how can the service provider know the statistics of > a > particular VBR stream? These can only be specified over a large number of > similar calls and will depend, for instance, on who is speaking, the > nature > of the speech interaction etc etc. They can only be measured not > calculated. The service provider is in no better position to measure > these > than the transport network operator and, in fact, where no gateways are > involved, may not be able to. On the other hand the class of signal would > have to be signalled to the network operator for him to be able to > distinguish which class a particular measurement belonged to. e.g > voice/speech/data, codec type, conference, multicast etc. So I see no > purpose in trying to exchange statistics between the service provider > (application) and transport operator. I think peak bit rate is all that > can > be meaningfully excanged. The specification of media class is however > perhaps worth exploring. > > 4. The controlled category has always puzzled me. I only see two > possibilities. Either the requested QoS level is guaranteed (on a > statistical basis e.g 95% of all connections over a specified period) or > not > guaranteed. Is your controlled category a way of saying guaranteed, not > to > 95% but to some lower figure? If you can't put a percentage on it then it > seems it is plain and simple not guaranteed. Anything that is not > guaranteed to some specified statistical level is best effort and you > can't > say anything more about it. So I only see two categories here. > > In summary, I think we need to do three things in Annex N. > > a) Figure out the QoS information to be exchanged within the Application > between service providers and end users. This will go in H.225.0 and > H.245. > > b) Figure out how we are going to signal QoS and media information between > the application (service providers) and transport domains (IP or ATM > networks etc). The info is basically delay, jitter, packet loss > requirements and peak bit rate. We need a protocol for this. > > c) we need to work out the interactions between the application QoS > signal > flows and the application/transport signal flows. I don't think we need > worry about how the transport network mechanisms assure the requested QoS > paramerters. RSVP/Intserv, Diffserv, MPLS, ATM, over provisioning are all > possibilities. > > Would welcome comments and views on the above. > > Mike > > > Mike Buckley > +44-1457-877718 (T) > +44-1457-877721 (F) > mikebuckley(a)44comms.com > > > ----- Original Message ----- > From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> > To: <ITU-SG16(a)MAILBAG.INTEL.COM> > Sent: Thursday, August 10, 2000 10:15 PM > Subject: H.323 QOS > > > Hi, Mike and All: > > It is time to discuss about H.323 QOS. > > I believe that we have an agreement as follows: > > · H.323 QOS MUST be backward compatible to support RSVP and ATM QOS as it > exists for H.323v2/v3/v4 > · Like H.323 spec, the application level H.323 QOS MUST be independent of > the transport layer QOS and should support all transport networks (e.g., > IP, > ATM) > · A mapping table between the H.323 QOS and the transport layer QOS (e.g., > IP QOS [DiffServ, RSVP, etc.], ATM QOS [CBR, rt-VBR, nrt-VBR, ABR, etc.]) > should be provided. > > From the H.323 multimedia application point of view, there are following > performance parameters can be used to characterize the traffic > characteristics: > > · Bitrate characteristics: Peak bit rate (PBR) or peak rate (PR), > Sustained > bit rate (SBR) or average rate (AR), minimum bit rate (MBR) or minimum > rate > (MR), and mean bust size (MBS) > · Delay and loss characteristics: end-to-end delay (EED) or delay, > end-to-end delay variation (EEDV) or delay variation (DV), and > bit-error-rate (BER) or (packet) loss rate (LR) > > We can now form a table with all parameters as follows: > > Table 1: H.323 Multimedia Application Performance Matrix > Audio (codecs)--- Video (codecs)--- Data > (T.120) > PBR/PR Yes/No/Value Yes/No/Value Yes/No/value > SBR/AR Yes/No/Value Yes/No/Value Yes/No/value > MBR/MR Yes/No/Value Yes/No/Value Yes/No/value > MBS Yes/No/Value Yes/No/Value Yes/No/value > EED/Delay Yes/No/Value Yes/No/Value Yes/No/value > EEDV/DV Yes/No/Value Yes/No/Value Yes/No/value > BER/LR Yes/No/Value Yes/No/Value Yes/No/value > > From the above table we will have the opportunity to choose each parameter > for each medium (audio, video, data) that makes sense from the > application's > and enduser's point of view. Again, these parameters can be specified as > follows: > > · Guaranteed: The value specified for each parameter MUST be guaranteed. > · Controlled: The value specified for each parameter MAY be satisfied as > far > as practicable (possibly with certain range), but definitely NOT > guaranteed. > · Best effort: No commitment will be made. > > Now each medium (e.g., audio, video, or data) will have different > categories > of performance matrix depending on its selection criteria and this can > also > be mapped to RSVP, ATM QOS, and others, if needed. > > Once we agree on this format, the next step is to create H.323 QOS > signaling > messages. > > This is my input for discussion in the upcoming Portland Q.13 meeting for > H.323 QOS. > > I like to see the comments from other members as well. > > Best regards, > Radhika R. Roy > AT&T > +1 732 420 1580 > rrroy(a)att.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

2 1

Re: H.323 QOS
by Chip Sharp 15 Aug '00

15 Aug '00

At 09:17 AM 8/15/00 -0400, Callaghan, Robert wrote: ...snip... >* My proposal is that the QoS is only negotiated with the original service >provider and that the QoS negotiation be performed between service >providers. Only the original service provider charges the user for the >service and this charge is split among the other service provider using a >process similar to that used by public telephone carriers today. All ISPs >do this today for basic service, so extending it to enhanced services is >reasonable. ...snip... Settlements in the ISP world are fairly byzantine and don't follow the model used by public telephone carriers today (possible exceptions are some of the arrangements for roaming and wholesale dial). Note the objections to draft Recommendation D.iii in SG3. What you suggest here would require a new business model, billing systems, OSS, etc. in the Service Providers(not to mention supporting the QOS in the first place). However, this is true for the alternatives proposed as well. :-) Chip ------------------------------------------------------------------- Chip Sharp Consulting Engineering Cisco Systems Reality - Love it or Change it. http://www.netaid.org ------------------------------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 0

Re: H.323 QOS
by Roy, Radhika R, ALCOO 15 Aug '00

15 Aug '00

Hi, Bob: H.323 QOS is only good for H.323 entities (e.g., terminals, GKs/BEs, MCUs, MCs, GWs, etc.) and signaling is done among these entities. This QOS spec is just another spec in H.323. So, H.323 QOS only sees what is happening in the H.323/H.225.0/H.245 level. Now there are implementation issues in the lower layer. For example, routers that need to transfer media between the terminals or between the GKs/BEs, etc are the functions of the lower network layer. These standards or implementation agreements/policies, etc. are separate from the H.323 layer. If the domains are created using the IP routers , H.323 will NOT see those. If domains are created including GKs, and BEs and media is routed via those GKs/BEs, those GKs/BEs will ONLY be involved for transferring of H.323 QOS information, not the media routing via the routers. So, there are well defined processes how intra-domain and inter-domain QOS will be implemented. Many works are going on in many standard organization to deal with the routing of media to meet the specific network layer QOS: IETF and other organizations. We are progressing step by step. Hope this will help. Best regards, Radhika R. Roy -----Original Message----- From: Callaghan, Robert [mailto:Robert.Callaghan@icn.siemens.com] Sent: Tuesday, August 15, 2000 10:31 AM To: Roy, Radhika R, ALCOO Cc: 'Mailing list for parties associated with ITU-T Study Group 16' Subject: RE: H.323 QOS Roy, What you say about H.245 is true is a serious limitation. H.245 is signaled end-to-end. There is no requirement that H.245 pass through the network in a route with any relationship with the media channels. Therefore, it will be difficult to extend H.245 for the control in intermediate domains along the path used by the media channels. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] Sent: Tuesday, August 15, 2000 9:16 AM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS Hi, Mike: Just for information, H.245 does many things. As I indicated earlier, one of the most important things of H.245 is the opening and closing of the logical channels that binds the application layer's logical connection abstractions to all transport network connections (e.g., ATM, etc). So, this is the fundamental mission of H.245 to provide the continuity between the application layer and the lower layer in a transport independent way using the universal abstractions. These abstractions can be for anything that we can think of. Hope this helps. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Tuesday, August 15, 2000 8:22 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Hi Radhika, This use of H.245 as a bridging mechanism is where I have difficulties. The original intenmt behind H.245 was media control and negociation. Transport mechanisms should not be signalled in H.245 or elsewhere in the application. This is entirely the business of the transport network provider. Unfortunately I will not be present in Portland, however, I am happy to continue this productive dialogue on the list with a view to providing a new draft in the next few weeks. Regards, Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 7:29 PM Subject: Re: H.323 QOS Hi, Mike: I guess that we have agreement on the fundamental basis. However, I have problems when you translate this in signaling terms. As I have explained earlier that we are following the exiting framework of H.323 which is the application layer, and H.323 is transported over one or different transport networks. H.323 uses H.245 as a common mechanism that helps to transports the abstraction of H.323 application signaling messages over any networks (e.g., IP, ATM, etc). You may look to the H.245 spec very carefully instead of making any generalized statement. H.245 provides the bridging between the application layer and transport layer mechanism. For example, H.245's OLC abstraction is the link for ATM network layer logical connection as well as for other transport networks. In the same token, H.323 QOS abstraction may also provide link to the lower transport layer QOS signaling mechanisms (e.g., RSVP, DiffServ, MPLS, ATM QOS, etc), if needed. H.323 DOES support RSVP and ATM QOS now. Please also see my reply embedded in you email [RRR]. Again, I would suggest to bring contributions explaining the solution and we will go from there. In absence of your contributions, I would suggest to provide comments on Appendix of H.323 QOS Annex N. We can then answer your questions step by step. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Monday, August 14, 2000 12:56 PM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Radhika, >However, this is only good for the single network. For example, >end-to-end RSVP or end-to-end ATM QOS. >If there are multiple networks or if a single IP network implements RSVP in >one domain, DiffServ in another domain, and MPLS in another domain, there is >no transparent H.323 QOS signaling mechanism that is universal on end-to-end >basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc >transparently This is the nub of the problem and I am afraid why this approach is flawed. [RRR] I am NOT afraid of anything. Rather we are solving all problems including the above as well. No one should be afraid of anything. The only thing that I can suggest is to bring contributions. We will go from there. Please remember that H.323 QOS supports RSVP and ATM QOS and we MUST provide backward compatibility. We will be waiting to see contributions from you to prove your points whether things are flawed or not. Please read Appnedix of H.323 QOS Annex N very carefully along with exiting H.323 and H.245 standard how they support H.323 QOS for RSVP and ATM QOS. >We have shown how the H.323 QOS can >be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. This mapping must be done within the transport plane not by the application. All the application needs to specify are the entries in your Table 1. i.e delay, jitter. packet loss and peak bit rate (the latter parameter for policy enforcement and resource reservation). [RRR] Please see my generalized clarification how H.245 provides translation between H.323 signaling schemes over the lower layer transport networks (e.g., IP, ATM, etc). The mechanism already exists in H.323 and this is the beauty of the transport independent H.323 application. Now there are two separate things: one is what the calling side of the application demands and what the called side of the application agrees on. This is called negotiation capability (e.g., choosing a particular type codec that has a certain bandwidth, jitter, and other requirements). How the choosing criteria is determined, the H.323 application is NOT aware of those things. It may depend on many criteria (e.g., policy, bandwidth, type of network [e.g., IP, ATM], pricing, security, personal preferences, etc.), but H.323 is not involved. These are separate issues and we are NOT addressing at the H.323 layer. I am still not clkear how you propose to signal these parameters to the transport plane. [RRR] It is NOT new in H.323, and this mechanism already exits. Please see the support of RSVP and ATM QOS in H.323/H.245 spec. We are not inventing anything NEW here. Then, if you read Appendix of H.323 QOS Annex N very carefully, you will find how it happening (whether you call it as transport plane or something else, it does not matter). I think we are getting loser to a common understanding. Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 2:37 PM Subject: Re: H.323 QOS Hi, Bob: I agree completely agree with you. In fact, we are all trying to achieve the same goal. For example, H.323 does supports QOS today via H.245. You can easily see that RSVP and ATM QOS are supported using H.245. The beauty of this approach is that H.245 is still transport independent. All we have done here is: the abstraction of H.245 has been used to support the RSVP and ATM QOS to implement the network layer QOS. However, this is only good for the single network. For example, end-to-end RSVP or end-to-end ATM QOS. If there are multiple networks or if a single IP network implements RSVP in one domain, DiffServ in another domain, and MPLS in another domain, there is no transparent H.323 QOS signaling mechanism that is universal on end-to-end basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc transparently. In Appendix of H.323 Annex N, we have done the same. We have the abstraction of H.323 QOS in the application layer. We have shown how the H.323 QOS can be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. It also provides the backward compatibility with the existing H.323 standard. However, we have done only for the pre-call setup signaling part. We have not done the call setup part yet. In the call setup part, we will include H.245 in a similar way what H.323 is supporting RSVP and ATM QOS today in a monolithic network. I appreciate your email. Best regards, Radhika R. Roy AT&T > -----Original Message----- > From: Callaghan, Robert [SMTP:Robert.Callaghan@icn.siemens.com] > Sent: Monday, August 14, 2000 9:08 AM > To: Roy, Radhika R, ALCOO > Cc: 'Mailing list for parties associated with ITU-T Study Group 16' > Subject: RE: H.323 QOS > > Roy, > > In my view, the network, as a minimum, needs only provide transport. > H.323 > is an application using this transport and is not different from any other > application being transported. Any application may request a desired > quality of service that the network may grant based on policies, service > level agreements, and availability. Each data connection used by an > application may request a different QOS. Most likely H.323 is such an > application as needing an enhanced QOS. This simple case should work. > This > is all that is required. > > In addition to transport, the network may optionally provide other > additional services. These services may include application layer > routing. > These optional services should be configured and indicated independently > from the basic transport QOS. > > It is correct that H.323, as an application, is (mostly) transport > independent. However, the interface between the application and the > transport layer is not transport independent. The interface specification > used to request a given QOS is totally dependant on the standards body > that > specified the transport layer; and for this there has been little or no > coordination. > > Because transport QOS over IP is based on IETF specifications, it is > necessary that the interface used to request a given QOS conform to the > appropriate IETF specification. If such an interface specification is not > available, that input might be provided to the appropriate IETF body as to > the requirements. > > I can see the endpoints negotiating the desired QOS base on need, price, > and > other considerations. For me, this is the limit to the application layer > involvement in QOS negotiation. At this point, the application > negotiations > with the transport provider as to the desired and available QOS. It is up > to the transport provider to arrange for the end-to-end QOS. (Again, it > is > not necessary for the transport network to know that H.323 is involved in > the transported data. In fact it may be encrypted in order to mask the > presence of voice transport.) > > For me, this is simple. > > Bob > > ------------------------------------------------------------------ > Robert Callaghan > Siemens Enterprise Networks > Tel: +1.561.923.1756 Fax: +1.561.923.1403 > Email: Robert.Callaghan(a)ICN.Siemens.com > ------------------------------------------------------------------ > > -----Original Message----- > From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] > Sent: Friday, August 11, 2000 7:59 AM > To: ITU-SG16(a)mailbag.cps.intel.com > Subject: Re: H.323 QOS > > Hi, Mike: > > Let me try again. > > What is the reference point of H.323 QOS? Is it not H.323? If it is so, > what > do we mean by H.323? > > The answer is: Audio (different codecs), Video (different codecs), and > Data > (T.120 applications) that are used by H.323. > > What are the QOS/performance characteristics of audio, video, and data > from > the application point of view that is generated by audio codecs, video > codecs, and data (T.120) applications? > > These QOS/performance characteristics come from the SOURCE codecs and data > applications. Per transport independent H.323 specifications, an enduser > express their QOS/performance requirements on end-to-end basis purely from > application point of view irrespective of the transport network (e.g., IP, > ATM, etc.). > > Moreover, H.323 is meant for the packet network, not for any > circuit-switched network like PSTN or ISDN. > > Let us NOT go beyond this before we start debating transport layer QOS or > service provider requirements. These are NOT the concern of H.323. H.323 > is > the transport independent application. > > H.323v2/v3/v4 has also provided mechanisms how RSVP and ATM QOS can be > used > for H.323 audio, video, and data. So, H.323 QOS that will be defined in > H.323 Annex N MUST provide mapping for the backward compatibility. It is a > requirement that MUST be met per the norm of ITU-T. > > So, what is left for mapping? Mapping is simply a by-product of the above > requirement. Mapping is simply a table, nothing else. > > Did I miss anything? > > Best regards, > Radhika R. Roy > AT&T > > -----Original Message----- > From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] > Sent: Thursday, August 10, 2000 10:19 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: Re: H.323 QOS > > > Radhika, > > Thanks for the input which I welcome as I will unfortunately not be > present > at Portland. > > Let me ask a few questions and make a few comments hopefully with the > intent > of opening up the debate. > > 1. I am not sure I understand your concept of a mapping table between the > H.323 QOS and the transport layer QoS. My understanding is that QoS is on > three levels: > > a) that specified from a service point of view between the user and > service > provider (e.g PSTN quality, conference quality etc) This is the domain of > the speech experts and can be characterised by Listener Speech Quaklity > (MOS), end to end delay, and absolute category rating, R. > > b) application specific parameters, (e.g. equipment delays, codec choice > and performance, codec frame size, packetisation arrangements, jitter > buffer > design, overall packet loss etc.) Optimisation of all these will > determine > what can be delivered in a). > > c) transport parameters for a given choice of application parameters. > This > boils down only to three parameters as far as I cna see: tranport network > delay, packet delay variation in the transport network and packet loss in > the transport network. Again these parameters will determine the results > in > a) for a given choice of the parameters in b). These parameters are > generic > from the perspective of the transport network. i.e the transport network > does not need to know the details of the application. > > So the sequence of cause and effect and control is: > > a) User requests QoS class from service provider, > b) Service provider determines application specific parameters in > conjunction with users equipment and other service providers, > c) Service provider requests required delay, delay variation and packet > loss from network provider. > > I see no need for mapping here. The only QoS info flows within the > application are specific to the application and those between the > application (service provider) and the transport network are generic. i.e. > delay, jitter and packet loss. Have I missed something? > > 2. The issue of bit rate and media stream statistics I think need to be > decoupled from QoS. These are specified to enable optimisation of > resources > within the transport network. They have no QoS significance from an > application point of view. i.e the apllication does not care about the > media stream bit rate and statistics but the transport network provider > does > as it eats up his resource. They may be used for policy enforcement > however > in the transport network so they do need to be agreed between service > provider and network operator. i.e the network operator agrees to provide > a > given QoS level (delay, jitter, packet loss) provided the media properties > are within an agreed profile (bit rate, flow statistics). > > 3. The next point is how can the service provider know the statistics of > a > particular VBR stream? These can only be specified over a large number of > similar calls and will depend, for instance, on who is speaking, the > nature > of the speech interaction etc etc. They can only be measured not > calculated. The service provider is in no better position to measure > these > than the transport network operator and, in fact, where no gateways are > involved, may not be able to. On the other hand the class of signal would > have to be signalled to the network operator for him to be able to > distinguish which class a particular measurement belonged to. e.g > voice/speech/data, codec type, conference, multicast etc. So I see no > purpose in trying to exchange statistics between the service provider > (application) and transport operator. I think peak bit rate is all that > can > be meaningfully excanged. The specification of media class is however > perhaps worth exploring. > > 4. The controlled category has always puzzled me. I only see two > possibilities. Either the requested QoS level is guaranteed (on a > statistical basis e.g 95% of all connections over a specified period) or > not > guaranteed. Is your controlled category a way of saying guaranteed, not > to > 95% but to some lower figure? If you can't put a percentage on it then it > seems it is plain and simple not guaranteed. Anything that is not > guaranteed to some specified statistical level is best effort and you > can't > say anything more about it. So I only see two categories here. > > In summary, I think we need to do three things in Annex N. > > a) Figure out the QoS information to be exchanged within the Application > between service providers and end users. This will go in H.225.0 and > H.245. > > b) Figure out how we are going to signal QoS and media information between > the application (service providers) and transport domains (IP or ATM > networks etc). The info is basically delay, jitter, packet loss > requirements and peak bit rate. We need a protocol for this. > > c) we need to work out the interactions between the application QoS > signal > flows and the application/transport signal flows. I don't think we need > worry about how the transport network mechanisms assure the requested QoS > paramerters. RSVP/Intserv, Diffserv, MPLS, ATM, over provisioning are all > possibilities. > > Would welcome comments and views on the above. > > Mike > > > Mike Buckley > +44-1457-877718 (T) > +44-1457-877721 (F) > mikebuckley(a)44comms.com > > > ----- Original Message ----- > From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> > To: <ITU-SG16(a)MAILBAG.INTEL.COM> > Sent: Thursday, August 10, 2000 10:15 PM > Subject: H.323 QOS > > > Hi, Mike and All: > > It is time to discuss about H.323 QOS. > > I believe that we have an agreement as follows: > > · H.323 QOS MUST be backward compatible to support RSVP and ATM QOS as it > exists for H.323v2/v3/v4 > · Like H.323 spec, the application level H.323 QOS MUST be independent of > the transport layer QOS and should support all transport networks (e.g., > IP, > ATM) > · A mapping table between the H.323 QOS and the transport layer QOS (e.g., > IP QOS [DiffServ, RSVP, etc.], ATM QOS [CBR, rt-VBR, nrt-VBR, ABR, etc.]) > should be provided. > > From the H.323 multimedia application point of view, there are following > performance parameters can be used to characterize the traffic > characteristics: > > · Bitrate characteristics: Peak bit rate (PBR) or peak rate (PR), > Sustained > bit rate (SBR) or average rate (AR), minimum bit rate (MBR) or minimum > rate > (MR), and mean bust size (MBS) > · Delay and loss characteristics: end-to-end delay (EED) or delay, > end-to-end delay variation (EEDV) or delay variation (DV), and > bit-error-rate (BER) or (packet) loss rate (LR) > > We can now form a table with all parameters as follows: > > Table 1: H.323 Multimedia Application Performance Matrix > Audio (codecs)--- Video (codecs)--- Data > (T.120) > PBR/PR Yes/No/Value Yes/No/Value Yes/No/value > SBR/AR Yes/No/Value Yes/No/Value Yes/No/value > MBR/MR Yes/No/Value Yes/No/Value Yes/No/value > MBS Yes/No/Value Yes/No/Value Yes/No/value > EED/Delay Yes/No/Value Yes/No/Value Yes/No/value > EEDV/DV Yes/No/Value Yes/No/Value Yes/No/value > BER/LR Yes/No/Value Yes/No/Value Yes/No/value > > From the above table we will have the opportunity to choose each parameter > for each medium (audio, video, data) that makes sense from the > application's > and enduser's point of view. Again, these parameters can be specified as > follows: > > · Guaranteed: The value specified for each parameter MUST be guaranteed. > · Controlled: The value specified for each parameter MAY be satisfied as > far > as practicable (possibly with certain range), but definitely NOT > guaranteed. > · Best effort: No commitment will be made. > > Now each medium (e.g., audio, video, or data) will have different > categories > of performance matrix depending on its selection criteria and this can > also > be mapped to RSVP, ATM QOS, and others, if needed. > > Once we agree on this format, the next step is to create H.323 QOS > signaling > messages. > > This is my input for discussion in the upcoming Portland Q.13 meeting for > H.323 QOS. > > I like to see the comments from other members as well. > > Best regards, > Radhika R. Roy > AT&T > +1 732 420 1580 > rrroy(a)att.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 0

Re: H.323 QOS
by Callaghan, Robert 15 Aug '00

15 Aug '00

Roy, What you say about H.245 is true is a serious limitation. H.245 is signaled end-to-end. There is no requirement that H.245 pass through the network in a route with any relationship with the media channels. Therefore, it will be difficult to extend H.245 for the control in intermediate domains along the path used by the media channels. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Enterprise Networks Tel: +1.561.923.1756 Fax: +1.561.923.1403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] Sent: Tuesday, August 15, 2000 9:16 AM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 QOS Hi, Mike: Just for information, H.245 does many things. As I indicated earlier, one of the most important things of H.245 is the opening and closing of the logical channels that binds the application layer's logical connection abstractions to all transport network connections (e.g., ATM, etc). So, this is the fundamental mission of H.245 to provide the continuity between the application layer and the lower layer in a transport independent way using the universal abstractions. These abstractions can be for anything that we can think of. Hope this helps. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Tuesday, August 15, 2000 8:22 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Hi Radhika, This use of H.245 as a bridging mechanism is where I have difficulties. The original intenmt behind H.245 was media control and negociation. Transport mechanisms should not be signalled in H.245 or elsewhere in the application. This is entirely the business of the transport network provider. Unfortunately I will not be present in Portland, however, I am happy to continue this productive dialogue on the list with a view to providing a new draft in the next few weeks. Regards, Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 7:29 PM Subject: Re: H.323 QOS Hi, Mike: I guess that we have agreement on the fundamental basis. However, I have problems when you translate this in signaling terms. As I have explained earlier that we are following the exiting framework of H.323 which is the application layer, and H.323 is transported over one or different transport networks. H.323 uses H.245 as a common mechanism that helps to transports the abstraction of H.323 application signaling messages over any networks (e.g., IP, ATM, etc). You may look to the H.245 spec very carefully instead of making any generalized statement. H.245 provides the bridging between the application layer and transport layer mechanism. For example, H.245's OLC abstraction is the link for ATM network layer logical connection as well as for other transport networks. In the same token, H.323 QOS abstraction may also provide link to the lower transport layer QOS signaling mechanisms (e.g., RSVP, DiffServ, MPLS, ATM QOS, etc), if needed. H.323 DOES support RSVP and ATM QOS now. Please also see my reply embedded in you email [RRR]. Again, I would suggest to bring contributions explaining the solution and we will go from there. In absence of your contributions, I would suggest to provide comments on Appendix of H.323 QOS Annex N. We can then answer your questions step by step. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Monday, August 14, 2000 12:56 PM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Radhika, >However, this is only good for the single network. For example, >end-to-end RSVP or end-to-end ATM QOS. >If there are multiple networks or if a single IP network implements RSVP in >one domain, DiffServ in another domain, and MPLS in another domain, there is >no transparent H.323 QOS signaling mechanism that is universal on end-to-end >basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc >transparently This is the nub of the problem and I am afraid why this approach is flawed. [RRR] I am NOT afraid of anything. Rather we are solving all problems including the above as well. No one should be afraid of anything. The only thing that I can suggest is to bring contributions. We will go from there. Please remember that H.323 QOS supports RSVP and ATM QOS and we MUST provide backward compatibility. We will be waiting to see contributions from you to prove your points whether things are flawed or not. Please read Appnedix of H.323 QOS Annex N very carefully along with exiting H.323 and H.245 standard how they support H.323 QOS for RSVP and ATM QOS. >We have shown how the H.323 QOS can >be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. This mapping must be done within the transport plane not by the application. All the application needs to specify are the entries in your Table 1. i.e delay, jitter. packet loss and peak bit rate (the latter parameter for policy enforcement and resource reservation). [RRR] Please see my generalized clarification how H.245 provides translation between H.323 signaling schemes over the lower layer transport networks (e.g., IP, ATM, etc). The mechanism already exists in H.323 and this is the beauty of the transport independent H.323 application. Now there are two separate things: one is what the calling side of the application demands and what the called side of the application agrees on. This is called negotiation capability (e.g., choosing a particular type codec that has a certain bandwidth, jitter, and other requirements). How the choosing criteria is determined, the H.323 application is NOT aware of those things. It may depend on many criteria (e.g., policy, bandwidth, type of network [e.g., IP, ATM], pricing, security, personal preferences, etc.), but H.323 is not involved. These are separate issues and we are NOT addressing at the H.323 layer. I am still not clkear how you propose to signal these parameters to the transport plane. [RRR] It is NOT new in H.323, and this mechanism already exits. Please see the support of RSVP and ATM QOS in H.323/H.245 spec. We are not inventing anything NEW here. Then, if you read Appendix of H.323 QOS Annex N very carefully, you will find how it happening (whether you call it as transport plane or something else, it does not matter). I think we are getting loser to a common understanding. Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 2:37 PM Subject: Re: H.323 QOS Hi, Bob: I agree completely agree with you. In fact, we are all trying to achieve the same goal. For example, H.323 does supports QOS today via H.245. You can easily see that RSVP and ATM QOS are supported using H.245. The beauty of this approach is that H.245 is still transport independent. All we have done here is: the abstraction of H.245 has been used to support the RSVP and ATM QOS to implement the network layer QOS. However, this is only good for the single network. For example, end-to-end RSVP or end-to-end ATM QOS. If there are multiple networks or if a single IP network implements RSVP in one domain, DiffServ in another domain, and MPLS in another domain, there is no transparent H.323 QOS signaling mechanism that is universal on end-to-end basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc transparently. In Appendix of H.323 Annex N, we have done the same. We have the abstraction of H.323 QOS in the application layer. We have shown how the H.323 QOS can be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. It also provides the backward compatibility with the existing H.323 standard. However, we have done only for the pre-call setup signaling part. We have not done the call setup part yet. In the call setup part, we will include H.245 in a similar way what H.323 is supporting RSVP and ATM QOS today in a monolithic network. I appreciate your email. Best regards, Radhika R. Roy AT&T > -----Original Message----- > From: Callaghan, Robert [SMTP:Robert.Callaghan@icn.siemens.com] > Sent: Monday, August 14, 2000 9:08 AM > To: Roy, Radhika R, ALCOO > Cc: 'Mailing list for parties associated with ITU-T Study Group 16' > Subject: RE: H.323 QOS > > Roy, > > In my view, the network, as a minimum, needs only provide transport. > H.323 > is an application using this transport and is not different from any other > application being transported. Any application may request a desired > quality of service that the network may grant based on policies, service > level agreements, and availability. Each data connection used by an > application may request a different QOS. Most likely H.323 is such an > application as needing an enhanced QOS. This simple case should work. > This > is all that is required. > > In addition to transport, the network may optionally provide other > additional services. These services may include application layer > routing. > These optional services should be configured and indicated independently > from the basic transport QOS. > > It is correct that H.323, as an application, is (mostly) transport > independent. However, the interface between the application and the > transport layer is not transport independent. The interface specification > used to request a given QOS is totally dependant on the standards body > that > specified the transport layer; and for this there has been little or no > coordination. > > Because transport QOS over IP is based on IETF specifications, it is > necessary that the interface used to request a given QOS conform to the > appropriate IETF specification. If such an interface specification is not > available, that input might be provided to the appropriate IETF body as to > the requirements. > > I can see the endpoints negotiating the desired QOS base on need, price, > and > other considerations. For me, this is the limit to the application layer > involvement in QOS negotiation. At this point, the application > negotiations > with the transport provider as to the desired and available QOS. It is up > to the transport provider to arrange for the end-to-end QOS. (Again, it > is > not necessary for the transport network to know that H.323 is involved in > the transported data. In fact it may be encrypted in order to mask the > presence of voice transport.) > > For me, this is simple. > > Bob > > ------------------------------------------------------------------ > Robert Callaghan > Siemens Enterprise Networks > Tel: +1.561.923.1756 Fax: +1.561.923.1403 > Email: Robert.Callaghan(a)ICN.Siemens.com > ------------------------------------------------------------------ > > -----Original Message----- > From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] > Sent: Friday, August 11, 2000 7:59 AM > To: ITU-SG16(a)mailbag.cps.intel.com > Subject: Re: H.323 QOS > > Hi, Mike: > > Let me try again. > > What is the reference point of H.323 QOS? Is it not H.323? If it is so, > what > do we mean by H.323? > > The answer is: Audio (different codecs), Video (different codecs), and > Data > (T.120 applications) that are used by H.323. > > What are the QOS/performance characteristics of audio, video, and data > from > the application point of view that is generated by audio codecs, video > codecs, and data (T.120) applications? > > These QOS/performance characteristics come from the SOURCE codecs and data > applications. Per transport independent H.323 specifications, an enduser > express their QOS/performance requirements on end-to-end basis purely from > application point of view irrespective of the transport network (e.g., IP, > ATM, etc.). > > Moreover, H.323 is meant for the packet network, not for any > circuit-switched network like PSTN or ISDN. > > Let us NOT go beyond this before we start debating transport layer QOS or > service provider requirements. These are NOT the concern of H.323. H.323 > is > the transport independent application. > > H.323v2/v3/v4 has also provided mechanisms how RSVP and ATM QOS can be > used > for H.323 audio, video, and data. So, H.323 QOS that will be defined in > H.323 Annex N MUST provide mapping for the backward compatibility. It is a > requirement that MUST be met per the norm of ITU-T. > > So, what is left for mapping? Mapping is simply a by-product of the above > requirement. Mapping is simply a table, nothing else. > > Did I miss anything? > > Best regards, > Radhika R. Roy > AT&T > > -----Original Message----- > From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] > Sent: Thursday, August 10, 2000 10:19 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: Re: H.323 QOS > > > Radhika, > > Thanks for the input which I welcome as I will unfortunately not be > present > at Portland. > > Let me ask a few questions and make a few comments hopefully with the > intent > of opening up the debate. > > 1. I am not sure I understand your concept of a mapping table between the > H.323 QOS and the transport layer QoS. My understanding is that QoS is on > three levels: > > a) that specified from a service point of view between the user and > service > provider (e.g PSTN quality, conference quality etc) This is the domain of > the speech experts and can be characterised by Listener Speech Quaklity > (MOS), end to end delay, and absolute category rating, R. > > b) application specific parameters, (e.g. equipment delays, codec choice > and performance, codec frame size, packetisation arrangements, jitter > buffer > design, overall packet loss etc.) Optimisation of all these will > determine > what can be delivered in a). > > c) transport parameters for a given choice of application parameters. > This > boils down only to three parameters as far as I cna see: tranport network > delay, packet delay variation in the transport network and packet loss in > the transport network. Again these parameters will determine the results > in > a) for a given choice of the parameters in b). These parameters are > generic > from the perspective of the transport network. i.e the transport network > does not need to know the details of the application. > > So the sequence of cause and effect and control is: > > a) User requests QoS class from service provider, > b) Service provider determines application specific parameters in > conjunction with users equipment and other service providers, > c) Service provider requests required delay, delay variation and packet > loss from network provider. > > I see no need for mapping here. The only QoS info flows within the > application are specific to the application and those between the > application (service provider) and the transport network are generic. i.e. > delay, jitter and packet loss. Have I missed something? > > 2. The issue of bit rate and media stream statistics I think need to be > decoupled from QoS. These are specified to enable optimisation of > resources > within the transport network. They have no QoS significance from an > application point of view. i.e the apllication does not care about the > media stream bit rate and statistics but the transport network provider > does > as it eats up his resource. They may be used for policy enforcement > however > in the transport network so they do need to be agreed between service > provider and network operator. i.e the network operator agrees to provide > a > given QoS level (delay, jitter, packet loss) provided the media properties > are within an agreed profile (bit rate, flow statistics). > > 3. The next point is how can the service provider know the statistics of > a > particular VBR stream? These can only be specified over a large number of > similar calls and will depend, for instance, on who is speaking, the > nature > of the speech interaction etc etc. They can only be measured not > calculated. The service provider is in no better position to measure > these > than the transport network operator and, in fact, where no gateways are > involved, may not be able to. On the other hand the class of signal would > have to be signalled to the network operator for him to be able to > distinguish which class a particular measurement belonged to. e.g > voice/speech/data, codec type, conference, multicast etc. So I see no > purpose in trying to exchange statistics between the service provider > (application) and transport operator. I think peak bit rate is all that > can > be meaningfully excanged. The specification of media class is however > perhaps worth exploring. > > 4. The controlled category has always puzzled me. I only see two > possibilities. Either the requested QoS level is guaranteed (on a > statistical basis e.g 95% of all connections over a specified period) or > not > guaranteed. Is your controlled category a way of saying guaranteed, not > to > 95% but to some lower figure? If you can't put a percentage on it then it > seems it is plain and simple not guaranteed. Anything that is not > guaranteed to some specified statistical level is best effort and you > can't > say anything more about it. So I only see two categories here. > > In summary, I think we need to do three things in Annex N. > > a) Figure out the QoS information to be exchanged within the Application > between service providers and end users. This will go in H.225.0 and > H.245. > > b) Figure out how we are going to signal QoS and media information between > the application (service providers) and transport domains (IP or ATM > networks etc). The info is basically delay, jitter, packet loss > requirements and peak bit rate. We need a protocol for this. > > c) we need to work out the interactions between the application QoS > signal > flows and the application/transport signal flows. I don't think we need > worry about how the transport network mechanisms assure the requested QoS > paramerters. RSVP/Intserv, Diffserv, MPLS, ATM, over provisioning are all > possibilities. > > Would welcome comments and views on the above. > > Mike > > > Mike Buckley > +44-1457-877718 (T) > +44-1457-877721 (F) > mikebuckley(a)44comms.com > > > ----- Original Message ----- > From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> > To: <ITU-SG16(a)MAILBAG.INTEL.COM> > Sent: Thursday, August 10, 2000 10:15 PM > Subject: H.323 QOS > > > Hi, Mike and All: > > It is time to discuss about H.323 QOS. > > I believe that we have an agreement as follows: > > · H.323 QOS MUST be backward compatible to support RSVP and ATM QOS as it > exists for H.323v2/v3/v4 > · Like H.323 spec, the application level H.323 QOS MUST be independent of > the transport layer QOS and should support all transport networks (e.g., > IP, > ATM) > · A mapping table between the H.323 QOS and the transport layer QOS (e.g., > IP QOS [DiffServ, RSVP, etc.], ATM QOS [CBR, rt-VBR, nrt-VBR, ABR, etc.]) > should be provided. > > From the H.323 multimedia application point of view, there are following > performance parameters can be used to characterize the traffic > characteristics: > > · Bitrate characteristics: Peak bit rate (PBR) or peak rate (PR), > Sustained > bit rate (SBR) or average rate (AR), minimum bit rate (MBR) or minimum > rate > (MR), and mean bust size (MBS) > · Delay and loss characteristics: end-to-end delay (EED) or delay, > end-to-end delay variation (EEDV) or delay variation (DV), and > bit-error-rate (BER) or (packet) loss rate (LR) > > We can now form a table with all parameters as follows: > > Table 1: H.323 Multimedia Application Performance Matrix > Audio (codecs)--- Video (codecs)--- Data > (T.120) > PBR/PR Yes/No/Value Yes/No/Value Yes/No/value > SBR/AR Yes/No/Value Yes/No/Value Yes/No/value > MBR/MR Yes/No/Value Yes/No/Value Yes/No/value > MBS Yes/No/Value Yes/No/Value Yes/No/value > EED/Delay Yes/No/Value Yes/No/Value Yes/No/value > EEDV/DV Yes/No/Value Yes/No/Value Yes/No/value > BER/LR Yes/No/Value Yes/No/Value Yes/No/value > > From the above table we will have the opportunity to choose each parameter > for each medium (audio, video, data) that makes sense from the > application's > and enduser's point of view. Again, these parameters can be specified as > follows: > > · Guaranteed: The value specified for each parameter MUST be guaranteed. > · Controlled: The value specified for each parameter MAY be satisfied as > far > as practicable (possibly with certain range), but definitely NOT > guaranteed. > · Best effort: No commitment will be made. > > Now each medium (e.g., audio, video, or data) will have different > categories > of performance matrix depending on its selection criteria and this can > also > be mapped to RSVP, ATM QOS, and others, if needed. > > Once we agree on this format, the next step is to create H.323 QOS > signaling > messages. > > This is my input for discussion in the upcoming Portland Q.13 meeting for > H.323 QOS. > > I like to see the comments from other members as well. > > Best regards, > Radhika R. Roy > AT&T > +1 732 420 1580 > rrroy(a)att.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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Re: H.323 QOS
by Roy, Radhika R, ALCOO 15 Aug '00

15 Aug '00

Hi, Mike: I guess that we have agreement on the fundamental basis. However, I have problems when you translate this in signaling terms. As I have explained earlier that we are following the exiting framework of H.323 which is the application layer, and H.323 is transported over one or different transport networks. H.323 uses H.245 as a common mechanism that helps to transports the abstraction of H.323 application signaling messages over any networks (e.g., IP, ATM, etc). You may look to the H.245 spec very carefully instead of making any generalized statement. H.245 provides the bridging between the application layer and transport layer mechanism. For example, H.245's OLC abstraction is the link for ATM network layer logical connection as well as for other transport networks. In the same token, H.323 QOS abstraction may also provide link to the lower transport layer QOS signaling mechanisms (e.g., RSVP, DiffServ, MPLS, ATM QOS, etc), if needed. H.323 DOES support RSVP and ATM QOS now. Please also see my reply embedded in you email [RRR]. Again, I would suggest to bring contributions explaining the solution and we will go from there. In absence of your contributions, I would suggest to provide comments on Appendix of H.323 QOS Annex N. We can then answer your questions step by step. Best regards, Radhika R. Roy AT&T -----Original Message----- From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] Sent: Monday, August 14, 2000 12:56 PM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 QOS Radhika, >However, this is only good for the single network. For example, >end-to-end RSVP or end-to-end ATM QOS. >If there are multiple networks or if a single IP network implements RSVP in >one domain, DiffServ in another domain, and MPLS in another domain, there is >no transparent H.323 QOS signaling mechanism that is universal on end-to-end >basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc >transparently This is the nub of the problem and I am afraid why this approach is flawed. [RRR] I am NOT afraid of anything. Rather we are solving all problems including the above as well. No one should be afraid of anything. The only thing that I can suggest is to bring contributions. We will go from there. Please remember that H.323 QOS supports RSVP and ATM QOS and we MUST provide backward compatibility. We will be waiting to see contributions from you to prove your points whether things are flawed or not. Please read Appnedix of H.323 QOS Annex N very carefully along with exiting H.323 and H.245 standard how they support H.323 QOS for RSVP and ATM QOS. >We have shown how the H.323 QOS can >be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. This mapping must be done within the transport plane not by the application. All the application needs to specify are the entries in your Table 1. i.e delay, jitter. packet loss and peak bit rate (the latter parameter for policy enforcement and resource reservation). [RRR] Please see my generalized clarification how H.245 provides translation between H.323 signaling schemes over the lower layer transport networks (e.g., IP, ATM, etc). The mechanism already exists in H.323 and this is the beauty of the transport independent H.323 application. Now there are two separate things: one is what the calling side of the application demands and what the called side of the application agrees on. This is called negotiation capability (e.g., choosing a particular type codec that has a certain bandwidth, jitter, and other requirements). How the choosing criteria is determined, the H.323 application is NOT aware of those things. It may depend on many criteria (e.g., policy, bandwidth, type of network [e.g., IP, ATM], pricing, security, personal preferences, etc.), but H.323 is not involved. These are separate issues and we are NOT addressing at the H.323 layer. I am still not clkear how you propose to signal these parameters to the transport plane. [RRR] It is NOT new in H.323, and this mechanism already exits. Please see the support of RSVP and ATM QOS in H.323/H.245 spec. We are not inventing anything NEW here. Then, if you read Appendix of H.323 QOS Annex N very carefully, you will find how it happening (whether you call it as transport plane or something else, it does not matter). I think we are getting loser to a common understanding. Mike Mike Buckley +44-1457-877718 (T) +44-1457-877721 (F) mikebuckley(a)44comms.com ----- Original Message ----- From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> To: <ITU-SG16(a)MAILBAG.INTEL.COM> Sent: Monday, August 14, 2000 2:37 PM Subject: Re: H.323 QOS Hi, Bob: I agree completely agree with you. In fact, we are all trying to achieve the same goal. For example, H.323 does supports QOS today via H.245. You can easily see that RSVP and ATM QOS are supported using H.245. The beauty of this approach is that H.245 is still transport independent. All we have done here is: the abstraction of H.245 has been used to support the RSVP and ATM QOS to implement the network layer QOS. However, this is only good for the single network. For example, end-to-end RSVP or end-to-end ATM QOS. If there are multiple networks or if a single IP network implements RSVP in one domain, DiffServ in another domain, and MPLS in another domain, there is no transparent H.323 QOS signaling mechanism that is universal on end-to-end basis so that it can be mapped over the RSVP, DiffServ, MPLS, ATM QOS, etc transparently. In Appendix of H.323 Annex N, we have done the same. We have the abstraction of H.323 QOS in the application layer. We have shown how the H.323 QOS can be mapped over the RSVP, DiffServ, ATM QOS, etc. if needed. It also provides the backward compatibility with the existing H.323 standard. However, we have done only for the pre-call setup signaling part. We have not done the call setup part yet. In the call setup part, we will include H.245 in a similar way what H.323 is supporting RSVP and ATM QOS today in a monolithic network. I appreciate your email. Best regards, Radhika R. Roy AT&T > -----Original Message----- > From: Callaghan, Robert [SMTP:Robert.Callaghan@icn.siemens.com] > Sent: Monday, August 14, 2000 9:08 AM > To: Roy, Radhika R, ALCOO > Cc: 'Mailing list for parties associated with ITU-T Study Group 16' > Subject: RE: H.323 QOS > > Roy, > > In my view, the network, as a minimum, needs only provide transport. > H.323 > is an application using this transport and is not different from any other > application being transported. Any application may request a desired > quality of service that the network may grant based on policies, service > level agreements, and availability. Each data connection used by an > application may request a different QOS. Most likely H.323 is such an > application as needing an enhanced QOS. This simple case should work. > This > is all that is required. > > In addition to transport, the network may optionally provide other > additional services. These services may include application layer > routing. > These optional services should be configured and indicated independently > from the basic transport QOS. > > It is correct that H.323, as an application, is (mostly) transport > independent. However, the interface between the application and the > transport layer is not transport independent. The interface specification > used to request a given QOS is totally dependant on the standards body > that > specified the transport layer; and for this there has been little or no > coordination. > > Because transport QOS over IP is based on IETF specifications, it is > necessary that the interface used to request a given QOS conform to the > appropriate IETF specification. If such an interface specification is not > available, that input might be provided to the appropriate IETF body as to > the requirements. > > I can see the endpoints negotiating the desired QOS base on need, price, > and > other considerations. For me, this is the limit to the application layer > involvement in QOS negotiation. At this point, the application > negotiations > with the transport provider as to the desired and available QOS. It is up > to the transport provider to arrange for the end-to-end QOS. (Again, it > is > not necessary for the transport network to know that H.323 is involved in > the transported data. In fact it may be encrypted in order to mask the > presence of voice transport.) > > For me, this is simple. > > Bob > > ------------------------------------------------------------------ > Robert Callaghan > Siemens Enterprise Networks > Tel: +1.561.923.1756 Fax: +1.561.923.1403 > Email: Robert.Callaghan(a)ICN.Siemens.com > ------------------------------------------------------------------ > > -----Original Message----- > From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] > Sent: Friday, August 11, 2000 7:59 AM > To: ITU-SG16(a)mailbag.cps.intel.com > Subject: Re: H.323 QOS > > Hi, Mike: > > Let me try again. > > What is the reference point of H.323 QOS? Is it not H.323? If it is so, > what > do we mean by H.323? > > The answer is: Audio (different codecs), Video (different codecs), and > Data > (T.120 applications) that are used by H.323. > > What are the QOS/performance characteristics of audio, video, and data > from > the application point of view that is generated by audio codecs, video > codecs, and data (T.120) applications? > > These QOS/performance characteristics come from the SOURCE codecs and data > applications. Per transport independent H.323 specifications, an enduser > express their QOS/performance requirements on end-to-end basis purely from > application point of view irrespective of the transport network (e.g., IP, > ATM, etc.). > > Moreover, H.323 is meant for the packet network, not for any > circuit-switched network like PSTN or ISDN. > > Let us NOT go beyond this before we start debating transport layer QOS or > service provider requirements. These are NOT the concern of H.323. H.323 > is > the transport independent application. > > H.323v2/v3/v4 has also provided mechanisms how RSVP and ATM QOS can be > used > for H.323 audio, video, and data. So, H.323 QOS that will be defined in > H.323 Annex N MUST provide mapping for the backward compatibility. It is a > requirement that MUST be met per the norm of ITU-T. > > So, what is left for mapping? Mapping is simply a by-product of the above > requirement. Mapping is simply a table, nothing else. > > Did I miss anything? > > Best regards, > Radhika R. Roy > AT&T > > -----Original Message----- > From: Mike Buckley [mailto:mikebuckley@44COMMS.COM] > Sent: Thursday, August 10, 2000 10:19 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: Re: H.323 QOS > > > Radhika, > > Thanks for the input which I welcome as I will unfortunately not be > present > at Portland. > > Let me ask a few questions and make a few comments hopefully with the > intent > of opening up the debate. > > 1. I am not sure I understand your concept of a mapping table between the > H.323 QOS and the transport layer QoS. My understanding is that QoS is on > three levels: > > a) that specified from a service point of view between the user and > service > provider (e.g PSTN quality, conference quality etc) This is the domain of > the speech experts and can be characterised by Listener Speech Quaklity > (MOS), end to end delay, and absolute category rating, R. > > b) application specific parameters, (e.g. equipment delays, codec choice > and performance, codec frame size, packetisation arrangements, jitter > buffer > design, overall packet loss etc.) Optimisation of all these will > determine > what can be delivered in a). > > c) transport parameters for a given choice of application parameters. > This > boils down only to three parameters as far as I cna see: tranport network > delay, packet delay variation in the transport network and packet loss in > the transport network. Again these parameters will determine the results > in > a) for a given choice of the parameters in b). These parameters are > generic > from the perspective of the transport network. i.e the transport network > does not need to know the details of the application. > > So the sequence of cause and effect and control is: > > a) User requests QoS class from service provider, > b) Service provider determines application specific parameters in > conjunction with users equipment and other service providers, > c) Service provider requests required delay, delay variation and packet > loss from network provider. > > I see no need for mapping here. The only QoS info flows within the > application are specific to the application and those between the > application (service provider) and the transport network are generic. i.e. > delay, jitter and packet loss. Have I missed something? > > 2. The issue of bit rate and media stream statistics I think need to be > decoupled from QoS. These are specified to enable optimisation of > resources > within the transport network. They have no QoS significance from an > application point of view. i.e the apllication does not care about the > media stream bit rate and statistics but the transport network provider > does > as it eats up his resource. They may be used for policy enforcement > however > in the transport network so they do need to be agreed between service > provider and network operator. i.e the network operator agrees to provide > a > given QoS level (delay, jitter, packet loss) provided the media properties > are within an agreed profile (bit rate, flow statistics). > > 3. The next point is how can the service provider know the statistics of > a > particular VBR stream? These can only be specified over a large number of > similar calls and will depend, for instance, on who is speaking, the > nature > of the speech interaction etc etc. They can only be measured not > calculated. The service provider is in no better position to measure > these > than the transport network operator and, in fact, where no gateways are > involved, may not be able to. On the other hand the class of signal would > have to be signalled to the network operator for him to be able to > distinguish which class a particular measurement belonged to. e.g > voice/speech/data, codec type, conference, multicast etc. So I see no > purpose in trying to exchange statistics between the service provider > (application) and transport operator. I think peak bit rate is all that > can > be meaningfully excanged. The specification of media class is however > perhaps worth exploring. > > 4. The controlled category has always puzzled me. I only see two > possibilities. Either the requested QoS level is guaranteed (on a > statistical basis e.g 95% of all connections over a specified period) or > not > guaranteed. Is your controlled category a way of saying guaranteed, not > to > 95% but to some lower figure? If you can't put a percentage on it then it > seems it is plain and simple not guaranteed. Anything that is not > guaranteed to some specified statistical level is best effort and you > can't > say anything more about it. So I only see two categories here. > > In summary, I think we need to do three things in Annex N. > > a) Figure out the QoS information to be exchanged within the Application > between service providers and end users. This will go in H.225.0 and > H.245. > > b) Figure out how we are going to signal QoS and media information between > the application (service providers) and transport domains (IP or ATM > networks etc). The info is basically delay, jitter, packet loss > requirements and peak bit rate. We need a protocol for this. > > c) we need to work out the interactions between the application QoS > signal > flows and the application/transport signal flows. I don't think we need > worry about how the transport network mechanisms assure the requested QoS > paramerters. RSVP/Intserv, Diffserv, MPLS, ATM, over provisioning are all > possibilities. > > Would welcome comments and views on the above. > > Mike > > > Mike Buckley > +44-1457-877718 (T) > +44-1457-877721 (F) > mikebuckley(a)44comms.com > > > ----- Original Message ----- > From: "Roy, Radhika R, ALCOO" <rrroy(a)ATT.COM> > To: <ITU-SG16(a)MAILBAG.INTEL.COM> > Sent: Thursday, August 10, 2000 10:15 PM > Subject: H.323 QOS > > > Hi, Mike and All: > > It is time to discuss about H.323 QOS. > > I believe that we have an agreement as follows: > > · H.323 QOS MUST be backward compatible to support RSVP and ATM QOS as it > exists for H.323v2/v3/v4 > · Like H.323 spec, the application level H.323 QOS MUST be independent of > the transport layer QOS and should support all transport networks (e.g., > IP, > ATM) > · A mapping table between the H.323 QOS and the transport layer QOS (e.g., > IP QOS [DiffServ, RSVP, etc.], ATM QOS [CBR, rt-VBR, nrt-VBR, ABR, etc.]) > should be provided. > > From the H.323 multimedia application point of view, there are following > performance parameters can be used to characterize the traffic > characteristics: > > · Bitrate characteristics: Peak bit rate (PBR) or peak rate (PR), > Sustained > bit rate (SBR) or average rate (AR), minimum bit rate (MBR) or minimum > rate > (MR), and mean bust size (MBS) > · Delay and loss characteristics: end-to-end delay (EED) or delay, > end-to-end delay variation (EEDV) or delay variation (DV), and > bit-error-rate (BER) or (packet) loss rate (LR) > > We can now form a table with all parameters as follows: > > Table 1: H.323 Multimedia Application Performance Matrix > Audio (codecs)--- Video (codecs)--- Data > (T.120) > PBR/PR Yes/No/Value Yes/No/Value Yes/No/value > SBR/AR Yes/No/Value Yes/No/Value Yes/No/value > MBR/MR Yes/No/Value Yes/No/Value Yes/No/value > MBS Yes/No/Value Yes/No/Value Yes/No/value > EED/Delay Yes/No/Value Yes/No/Value Yes/No/value > EEDV/DV Yes/No/Value Yes/No/Value Yes/No/value > BER/LR Yes/No/Value Yes/No/Value Yes/No/value > > From the above table we will have the opportunity to choose each parameter > for each medium (audio, video, data) that makes sense from the > application's > and enduser's point of view. Again, these parameters can be specified as > follows: > > · Guaranteed: The value specified for each parameter MUST be guaranteed. > · Controlled: The value specified for each parameter MAY be satisfied as > far > as practicable (possibly with certain range), but definitely NOT > guaranteed. > · Best effort: No commitment will be made. > > Now each medium (e.g., audio, video, or data) will have different > categories > of performance matrix depending on its selection criteria and this can > also > be mapped to RSVP, ATM QOS, and others, if needed. > > Once we agree on this format, the next step is to create H.323 QOS > signaling > messages. > > This is my input for discussion in the upcoming Portland Q.13 meeting for > H.323 QOS. > > I like to see the comments from other members as well. > > Best regards, > Radhika R. Roy > AT&T > +1 732 420 1580 > rrroy(a)att.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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