January 2000 - sg16-avd - lists.packetizer.com

I'm out of the office (auto reply)
by Francois-Xavier Kowalski 11 Jan '00

11 Jan '00

Hello, I am absent from January 10 to January 24. During this time, I will not be able to access my e-mail. If necessary, please contact: Pierre Lebret - Hewlett-Packard Telecom Infrastructure Division phone: +33 (0) 4 76 14 57 21 e-mail: pierre_lebret(a)grenoble.hp.com Thank you. Francois-Xavier Kowalski.

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joint meeting with SG11
by /Q11, Q12, Q13 11 Jan '00

11 Jan '00

I have heard that we will have a joint meeting with SG11 the 14th - 18th feb week in Geneva.. Is this somehow true ??? Is their something planned ? If yes could someone tell me what is the agenda or items to be discussed?? Thank you Ameneh Zahir Alcatel

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Re: H.323 mobility: last call
by Jaakko Sundquist 10 Jan '00

10 Jan '00

Hi all, Unfortunately I can not attend the telephony conference this evening (yep, evening for us), but at least Senthil will be there representing Nokia. There doesn't seem to be any major issues that we would like to change in the draft Annex H (MTD-03c) at the moment, so if no major changes are introduced to it, I we are willing to be co-contributors of the contribution (that the draft will hopefully be) for the Geneva meeting. - Jaakko Sundquist ------------------------------------------------------- In a hole in the ground there lived a hobbit. Not a nasty, dirty, wet hole, filled with the ends of worms and an oozy smell, nor yet a dry, bare, sandy hole with nothing in it to sit down on or to eat: it was a hobbit-hole, and that means comfort. ------------------------------------------------------- -----Original Message----- From: EXT Roy, Radhika R, ALARC [mailto:rrroy@ATT.COM] Sent: Monday, January 10, 2000 3:18 PM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: H.323 mobility: last call Hi, Everyone: Ed Martinez has provided a good input with respect to the US SG-D meeting that the meeting will be held on January 18 (not the date what I expected before). Let us talk about the document MTD-3c as proposed. In addition, we can discuss more if we have time in today's conference call. Best Regards, Radhika R. Roy, AT&T H.323 Ad Hoc Mobility Group +1 732 420 1580 > -----Original Message----- > From: Edgar Martinez [1] [SMTP:martinze@CIG.MOT.COM] > Sent: Sunday, January 09, 2000 2:23 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: H.323 mobility: last call > Importance: High > > Dear H.323 Mobilty group, > > This maybe the last meeting with the U.S.A group. The > Study Group D meeting is set for Jan 18, 2000. Where > we need to have an agreed contribution from the mobile Ad-hoc > group so we can present it in the full Sg16 meeting in Geneva. > > I propose we go over MTD-3c which already includes > the Nokia contribution. Then go over the remaining contributions > and spend no more then 10 minutes on each. Whatever can be added > and agreed on will be included in the final MTD-3d. If we can not > agreed on adding anything after the MTD-3c review which will include > Nokia's updates, I propose to take MTD-3c as it is, to study group D > in washington d.c. for the Jan 18, 2000 meeting. > > What will be presented in Study group D is the H.323 mobilty document > outline and the contents we have agreed so far. > > --- > Conference call will be held as follows: > > Date: January 10, 2000 > Time: 8:00 AM to 10:00 AM (Pacific Standard Time (PST)) > Reservation # 13928768 > Number port reserved: 20 Ports > Conference Call Bridge call in number: +1 (415)-904-8877 > Passcode: 8813575 > > 1. Call to Order & Opening Remarks > 2. Attendance Registration > 4. Agenda Review and Approval: MTD-01f > 5. Review H.323 Mobility Ad Hoc Meeting report: MTD-02f > 6. Review Carry over contributions and review sequence proposal, (see > table 1 of MTD-01f) > 7. Discuss next conference call meetings > 8. Review Assignments > 9. Review Workplan > 10. Open Discussion > 11. Adjourn > > -- > Edgar Martinez - Principal Staff Engineer > Email mailto:martinze@cig.mot.com > FAX 1-847-632-3145 - - Voice 1-847-632-5278 > 1501 West Shure Drive, Arlington Hgts. IL 60004 > Public: TIPHON & Other Stds - http://people.itu.int/~emartine/ > Private:TIPHON & Other Stds - http://www.cig.mot.com/~martinze/

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Re: H.323 mobility: last call
by Frank Derks 10 Jan '00

10 Jan '00

Is there a location where I can download the MTD-3c document? The two links provided by Edgar do not work for me (ftp://standard.pictel.com/avc-site/Incoming/H323_Mobility/SG16_Mobility/ or http://people.itu.int/~emartine/temp/SG16-mobility/All_Confernce_Call_meeti… ). Regards, Frank ----------------------------------------------------- Frank Derks |Tel +31 35 6893238 | Advanced Development |Fax +31 35 6891030 | Philips Business Communications|P.O. Box 32 | |1200 JD Hilversum | |The Netherlands | ----------------------------------------------------| E-mail: mailto:frank.derks@philips.com | WWW: http://www.sopho.philips.com | ----------------------------------------------------- rrroy@ATT.COM@SMTP@MAILBAG.INTEL.COM on 10/01/2000 14:33:48 Please respond to ITU-SG16@MAILBAG.INTEL.COM@SMTP Sent by: ITU-SG16(a)MAILBAG.INTEL.COM To: ITU-SG16@MAILBAG.INTEL.COM@SMTP cc: Subject: Re: H.323 mobility: last call Classification: Restricted Hi, Everyone: Ed Martinez has provided a good input with respect to the US SG-D meeting that the meeting will be held on January 18 (not the date what I expected before). Let us talk about the document MTD-3c as proposed. In addition, we can discuss more if we have time in today's conference call. Best Regards, Radhika R. Roy, AT&T H.323 Ad Hoc Mobility Group +1 732 420 1580 > -----Original Message----- > From: Edgar Martinez [1] [SMTP:martinze@CIG.MOT.COM] > Sent: Sunday, January 09, 2000 2:23 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: H.323 mobility: last call > Importance: High > > Dear H.323 Mobilty group, > > This maybe the last meeting with the U.S.A group. The > Study Group D meeting is set for Jan 18, 2000. Where > we need to have an agreed contribution from the mobile Ad-hoc > group so we can present it in the full Sg16 meeting in Geneva. > > I propose we go over MTD-3c which already includes > the Nokia contribution. Then go over the remaining contributions > and spend no more then 10 minutes on each. Whatever can be added > and agreed on will be included in the final MTD-3d. If we can not > agreed on adding anything after the MTD-3c review which will include > Nokia's updates, I propose to take MTD-3c as it is, to study group D > in washington d.c. for the Jan 18, 2000 meeting. > > What will be presented in Study group D is the H.323 mobilty document > outline and the contents we have agreed so far. > > --- > Conference call will be held as follows: > > Date: January 10, 2000 > Time: 8:00 AM to 10:00 AM (Pacific Standard Time (PST)) > Reservation # 13928768 > Number port reserved: 20 Ports > Conference Call Bridge call in number: +1 (415)-904-8877 > Passcode: 8813575 > > 1. Call to Order & Opening Remarks > 2. Attendance Registration > 4. Agenda Review and Approval: MTD-01f > 5. Review H.323 Mobility Ad Hoc Meeting report: MTD-02f > 6. Review Carry over contributions and review sequence proposal, (see > table 1 of MTD-01f) > 7. Discuss next conference call meetings > 8. Review Assignments > 9. Review Workplan > 10. Open Discussion > 11. Adjourn > > -- > Edgar Martinez - Principal Staff Engineer > Email mailto:martinze@cig.mot.com > FAX 1-847-632-3145 - - Voice 1-847-632-5278 > 1501 West Shure Drive, Arlington Hgts. IL 60004 > Public: TIPHON & Other Stds - http://people.itu.int/~emartine/ > Private:TIPHON & Other Stds - http://www.cig.mot.com/~martinze/

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Re: H.323 mobility: last call
by Roy, Radhika R, ALARC 10 Jan '00

10 Jan '00

Hi, Everyone: Ed Martinez has provided a good input with respect to the US SG-D meeting that the meeting will be held on January 18 (not the date what I expected before). Let us talk about the document MTD-3c as proposed. In addition, we can discuss more if we have time in today's conference call. Best Regards, Radhika R. Roy, AT&T H.323 Ad Hoc Mobility Group +1 732 420 1580 > -----Original Message----- > From: Edgar Martinez [1] [SMTP:martinze@CIG.MOT.COM] > Sent: Sunday, January 09, 2000 2:23 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: H.323 mobility: last call > Importance: High > > Dear H.323 Mobilty group, > > This maybe the last meeting with the U.S.A group. The > Study Group D meeting is set for Jan 18, 2000. Where > we need to have an agreed contribution from the mobile Ad-hoc > group so we can present it in the full Sg16 meeting in Geneva. > > I propose we go over MTD-3c which already includes > the Nokia contribution. Then go over the remaining contributions > and spend no more then 10 minutes on each. Whatever can be added > and agreed on will be included in the final MTD-3d. If we can not > agreed on adding anything after the MTD-3c review which will include > Nokia's updates, I propose to take MTD-3c as it is, to study group D > in washington d.c. for the Jan 18, 2000 meeting. > > What will be presented in Study group D is the H.323 mobilty document > outline and the contents we have agreed so far. > > --- > Conference call will be held as follows: > > Date: January 10, 2000 > Time: 8:00 AM to 10:00 AM (Pacific Standard Time (PST)) > Reservation # 13928768 > Number port reserved: 20 Ports > Conference Call Bridge call in number: +1 (415)-904-8877 > Passcode: 8813575 > > 1. Call to Order & Opening Remarks > 2. Attendance Registration > 4. Agenda Review and Approval: MTD-01f > 5. Review H.323 Mobility Ad Hoc Meeting report: MTD-02f > 6. Review Carry over contributions and review sequence proposal, (see > table 1 of MTD-01f) > 7. Discuss next conference call meetings > 8. Review Assignments > 9. Review Workplan > 10. Open Discussion > 11. Adjourn > > -- > Edgar Martinez - Principal Staff Engineer > Email mailto:martinze@cig.mot.com > FAX 1-847-632-3145 - - Voice 1-847-632-5278 > 1501 West Shure Drive, Arlington Hgts. IL 60004 > Public: TIPHON & Other Stds - http://people.itu.int/~emartine/ > Private:TIPHON & Other Stds - http://www.cig.mot.com/~martinze/

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[Fwd: H.323 mobility: last call]
by Edgar Martinez [1] 09 Jan '00

09 Jan '00

You can pick the documents in: ftp://standard.pictel.com/avc-site/Incoming/H323_Mobility/SG16_Mobility/ or http://people.itu.int/~emartine/temp/SG16-mobility/All_Confernce_Call_meeti… -------- Original Message -------- Subject: H.323 mobility: last call Date: Sun, 09 Jan 2000 14:22:51 -0500 From: "Edgar Martinez [1]" <martinze(a)cig.mot.com> Organization: NSS-NAT To: "H.323 Mobility" <ITU-SG16(a)mailbag.cps.intel.com> Dear H.323 Mobilty group, This maybe the last meeting with the U.S.A group. The Study Group D meeting is set for Jan 18, 2000. Where we need to have an agreed contribution from the mobile Ad-hoc group so we can present it in the full Sg16 meeting in Geneva. I propose we go over MTD-3c which already includes the Nokia contribution. Then go over the remaining contributions and spend no more then 10 minutes on each. Whatever can be added and agreed on will be included in the final MTD-3d. If we can not agreed on adding anything after the MTD-3c review which will include Nokia's updates, I propose to take MTD-3c as it is, to study group D in washington d.c. for the Jan 18, 2000 meeting. What will be presented in Study group D is the H.323 mobilty document outline and the contents we have agreed so far. --- Conference call will be held as follows: Date: January 10, 2000 Time: 8:00 AM to 10:00 AM (Pacific Standard Time (PST)) Reservation # 13928768 Number port reserved: 20 Ports Conference Call Bridge call in number: +1 (415)-904-8877 Passcode: 8813575 1. Call to Order & Opening Remarks 2. Attendance Registration 4. Agenda Review and Approval: MTD-01f 5. Review H.323 Mobility Ad Hoc Meeting report: MTD-02f 6. Review Carry over contributions and review sequence proposal, (see table 1 of MTD-01f) 7. Discuss next conference call meetings 8. Review Assignments 9. Review Workplan 10. Open Discussion 11. Adjourn -- Edgar Martinez - Principal Staff Engineer Email mailto:martinze@cig.mot.com FAX 1-847-632-3145 - - Voice 1-847-632-5278 1501 West Shure Drive, Arlington Hgts. IL 60004 Public: TIPHON & Other Stds - http://people.itu.int/~emartine/ Private:TIPHON & Other Stds - http://www.cig.mot.com/~martinze/

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H.323 mobility: last call
by Edgar Martinez [1] 09 Jan '00

09 Jan '00

Dear H.323 Mobilty group, This maybe the last meeting with the U.S.A group. The Study Group D meeting is set for Jan 18, 2000. Where we need to have an agreed contribution from the mobile Ad-hoc group so we can present it in the full Sg16 meeting in Geneva. I propose we go over MTD-3c which already includes the Nokia contribution. Then go over the remaining contributions and spend no more then 10 minutes on each. Whatever can be added and agreed on will be included in the final MTD-3d. If we can not agreed on adding anything after the MTD-3c review which will include Nokia's updates, I propose to take MTD-3c as it is, to study group D in washington d.c. for the Jan 18, 2000 meeting. What will be presented in Study group D is the H.323 mobilty document outline and the contents we have agreed so far. --- Conference call will be held as follows: Date: January 10, 2000 Time: 8:00 AM to 10:00 AM (Pacific Standard Time (PST)) Reservation # 13928768 Number port reserved: 20 Ports Conference Call Bridge call in number: +1 (415)-904-8877 Passcode: 8813575 1. Call to Order & Opening Remarks 2. Attendance Registration 4. Agenda Review and Approval: MTD-01f 5. Review H.323 Mobility Ad Hoc Meeting report: MTD-02f 6. Review Carry over contributions and review sequence proposal, (see table 1 of MTD-01f) 7. Discuss next conference call meetings 8. Review Assignments 9. Review Workplan 10. Open Discussion 11. Adjourn -- Edgar Martinez - Principal Staff Engineer Email mailto:martinze@cig.mot.com FAX 1-847-632-3145 - - Voice 1-847-632-5278 1501 West Shure Drive, Arlington Hgts. IL 60004 Public: TIPHON & Other Stds - http://people.itu.int/~emartine/ Private:TIPHON & Other Stds - http://www.cig.mot.com/~martinze/

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H.225 Annex G and UsageIndication
by Michael Fortinsky 09 Jan '00

09 Jan '00

I have a question relating to H.225 Annex G, section 1.8.2.28 (Usage Indication). The standard says the following about the SourceAddress field: "SourceAddress E.164 or e-mail address of the caller party. In case of E.164 this designates the ANI/CLI." i.e., if the SourceAddress is an E.164 number, this refers to the ANI/CLI of the caller. Is this always true? Is AnnexG unnecessarily limiting the semantics of the SourceAddress field? I can think of a case when the AnnexG definition might be a problem. Think of a system where each subscriber in the system is assigned a globally unique "internet telephone number". In this case, the caller's identifier will look like an E.164 number, but it will not be the ANI/CLI. A border element or clearing house that assumes the E.164 is an ANI/CLI will be making a mistake. Does anyone have any ideas how this scenario can be handled within the context of AnnexG? Michael Fortinsky ----------------------------------------------------------------- Senior Program Manager, IP Telephony Group, VocalTec Communications Ltd. Email: mike(a)vocaltec.com Tel: 972 9 9707768 Fax: 972 9 9561867

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minor problems in H.225 Annex G
by Michael Fortinsky 06 Jan '00

06 Jan '00

Here are a few problems I've found in H.225 Annex G. They are problems of an "editorial" nature, but should probably be fixed in the near term (Geneva?). (1) Section 1.7.1 - The end of the first paragraph states the following: " (Note that since " * " is a meaningful character, the template actually includes a Boolean flag to indicate whether the address is specific or not. These examples use " * " to indicate a wild card, but the actual representation in the template is through the Boolean flag.) " In the latest version of the Annex, there is no longer a boolean flag in the template. Each pattern in a template explicitly indicates whether it is a specific or wildcard pattern. I suggest to change the wording to: " (Note that templates do not use the " * " character to indicate whether an address is specific or not because the " * " character can have other meanings - e.g., within an AliasAddress. Instead, the template explicitly specifies whether an address is a specific or a wildcard address. For illustrative purposes, the examples that follow use " * " to indicate a wildcard address.) " (2) Section 1.7.1.2 - The first paragraph states: "A border element may request the statically configured templates from another border element." I think there is no reason to differentiate between templates that were configured statically and those received dynamically. I suggest the wording: "A border element may request templates from another border element." (3) Section 1.8.2.1 The third field, gatekeeperID, should be called elementIdentifier, for the following reasons: - a gatekeeper does not own a descriptor - a border element does - to be consistent with other messages (which use the elementIdentifier to represent the id of the relevant border element) The Field and Description for this field should be changed to: Field Description ================================= elementIdentifier This is a text identifier that indicates the owner of the descriptor (i.e., the border element that created this message The ASN.1 for Descriptor should also be changed from: Descriptor ::= SEQUENCE { descriptorInfo DescriptorInfo, templates SEQUENCE OF AddressTemplate, gatekeeperID GatekeeperIdentifier OPTIONAL, ... } to: Descriptor ::= SEQUENCE { descriptorInfo DescriptorInfo, templates SEQUENCE OF AddressTemplate, elementIdentifier ElementIdentifier OPTIONAL, ... } (4) Section 1.8.2.3.3 - There is a typo in the Description of the transportQoS field. It currently states: transportQoS Indicates where the responsibility lies for resource reservation for the all made through this contact. I suggest: transportQoS Indicates where the responsibility lies for resource reservation for a call made through this contact. (5) Section 1.8.2.5 - There is a typo - the term SecurityCapability is misspelled. (6) Section 2 (ASN.1 definitions) - the specification of serviceID is not correct. It reads: serviceID ::= GloballyUniqueID The "s" in serviceID should be capitalized. The correct line is: ServiceID ::= GloballyUniqueID This is actually a more serious problem, because it will cause ASN.1 compilation problems. Michael Fortinsky ----------------------------------------------------------------- Program Manager, Servers Group R&D, VocalTec Communications Ltd. Email: mike(a)vocaltec.com Tel: 972 9 9707768 Fax: 972 9 9561867

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Re: Closing Q.931 TCP connection..
by Callaghan, Robert 06 Jan '00

06 Jan '00

Boaz, This is a missing point in this discussion. The proposal is to close the Call Signaling channel because it is anticipated that there is no additional use for the channel. If this anticipation is wrong, a procedure is required to reopen the call signaling channel and to resynchronize all the state information. What is the proposed procedure for reopening this channel? Please do not state that your application does not use H.450 or any other subsequent use of the call signaling channel. Even though your gatekeeper does not use H.450, my endpoint does and interworking is required. Bob ------------------------------------------------------------------ Robert Callaghan Siemens Information and Communication Networks Tel: +1.561.997.3756 Fax: +1.561.997.3403 Email: Robert.Callaghan(a)ICN.Siemens.com ------------------------------------------------------------------ -----Original Message----- From: Boaz Michaely [mailto:Boaz_Michaely@VOCALTEC.COM] Sent: Wednesday, January 05, 2000 4:47 PM To: ITU-SG16(a)mailbag.cps.intel.com Subject: Re: Closing Q.931 TCP connection.. Hi Chris, Glad I caught your interest ... Let me clarify some points which seem to have been misunderstood: (I'll try shorthand this time :-) 1. The case is NOT made for the GK not being the point for SETUP to call. Quite the reverse: I propose that the GK *is* the single point to call, and that it executes load balancing logic to distribute the H.245 negotiations elsewhere. 2. Varying the address given in AnnexG defetes no 1. 3. H.450.2 has nothing to do with it as the call is NOT being redirected. It is merely being decomposed. 4. You are NOT required to remove the call signalling at all. I'm afraid my point has been completely missed : I call for ALLOWING the close of the "Q.931" TCP signalling channel, while maintaining only the MEDIA CONTROL (h.245) channel open. 5. I too suspect that this scenario "just works", which is why I find it attractive to continue to allow closing of the Q.931 channel mid-call, WITHOUT killing the call . (again - this is perfectly legal today). We may need to update the standard, though, in order to solve the problems that Paul identified ! Thanks for your thoughts, Boaz -------- On 04/01/2000 06:27 PM GMT Chris Wayman Purvis <cwp(a)ISDN-COMMS.CO.UK> wrote: Boaz, The beast you describe is very strange and, as Paul says, interesting. Permit me to copy a para from your mail, in order to take issue with it! >> Once a SETUP message comes in, the GK replies with an H.245 address of the >> applicable MG. Note that the GK has to be the point of call for SETUP, >> since it may use the information in the SETUP message for finding the >> applicable MG (i.e. using CLI and/or DNIS), as well as it performs load >> balancing on the MGs. I'm not convinced the case is made here for the GK not being the point for SETUP to call. As you postulate the use of "SendSetup" Annex G messages, load balancing can be achieved adequately by varying the address given there. I'm hazy about how much information Annex G gives you as to the source of a call, but would hope that the sort of information that will be useful here (such as country of origin of the call) would be available (maybe an Annex G expert can help here?)? Even given the GK as the destination for the original setup message, H.450.2(? I think it's 2!) would allow the call to be redirected elsewhere once the GK has looked at that message. What I'm saying in general is that I'd hope to be able to achieve your application without requiring the removal of the call signalling channel, and I'm sure there are at least two ways of doing it, depending on precisely what you require, without any new standards needing to be written. In most cases I'm agnostic about Paul's point of a gatekeeper routing call control (H.225.0) but not connection control (H.245). In my view everything just works. BUT I believe that in order for everything to "just work" the assumption has to be there that the call control channel doesn't die mid-call. Regards, Chris "Paul E. Jones" wrote: > > Boaz, > > I do consistently argue against closing the call signaling channel. But > there are good reasons for this: > 1) Many devices out there clear the call when the channel is closed (yes, > this is wrong, but it's a fact of life :-) > 2) Closing the call signaling channel prohibits (or complicates) the use of > supplementary services and other in-band signaling. > > The text to which Chris Purvis refers is section 6.1. Here is an extraction > of that text: > ``For the gatekeeper mediated call signalling case (see Figure 8/H.323), the > terminals shall keep the reliable port active throughout the call. However, > the gatekeeper may choose to close this signalling channel, but should keep > the channel open for calls that involve gateways. This will allow the > end-to-end transmission of Q.931 information elements such as display > information.'' > > What you propose below is interesting and may yield a more scalable > solution. Perhaps this should be explored. I might note, though, that at > the moment, such a configuration is "undefined". According to H.323, > routing the call signaling through a Gatekeeper, but not the H.245, is "for > further study". It might be interesting to read contributions from you that > might open this area for study. > > Best Regards, > Paul > > ----- Original Message ----- > From: "Boaz Michaely" <Boaz_Michaely(a)vocaltec.com> > To: "Paul E. Jones" <paul.jones(a)ties.itu.int> > Cc: <h323implementors(a)imtc.org>; <itu-sg16(a)mailbag.cps.intel.com> > Sent: Thursday, December 30, 1999 7:40 PM > Subject: Re: Closing Q.931 TCP connection.. > > > Happy new Y2K ! > > Your consistent argueing against closing the Q.931 sig. channel, is > > appreciable, and I share your concern for many service scenarios. (I guess > > we'll talk more about this in February, which is why the ITU-SG16 list is > > copied) > > However, in the following scenario, it seems highly desireable to be able > > to close the sig. channel: > > (if this has been described before, please forgive my ignorance) > > > > Think of a scaleable IVR server farm which is implemented using multiple > > MG's, each capable of H.245, RTP/RTCP, and a very simple control protocol > > (H.248 ?). A single GRC GK, which is also an AnnexG Border Element is used > > as the single entry into this port-dense system. > > This GK may be addressed using LRQ from another domain (e.g. that of an > > ITSP). In addition, it publishes its own address using "SendSetup" type of > > addressing in the AnnexG templates that it publishes. > > > > Once a SETUP message comes in, the GK replies with an H.245 address of the > > applicable MG. Note that the GK has to be the point of call for SETUP, > > since it may use the information in the SETUP message for finding the > > applicable MG > > (i.e. using CLI and/or DNIS), as well as it performs load balancing on the > > MGs. > > Now the audio session is connected and the call takes place, while the MG > > handles the DTMFs and all the logic. > > Let's assume that there are no changes in the call routing from this point > > on (which is typically the case in, say, automatic banking systems etc.) > > GK intervention is not required any more until the call is done. > > > > It would be nice if the GK could get rid of the dangling Q.931 TCP > > connection, while the RTP call continues until it is disconnected by the > > human caller. If I understand correctly, this is a perfectly legitimate > > behaviour using the existing standard. (I trust this is true for all > > versions ?) > > > > Assuming this scenario is valid (have I overlooked anything ?) can we find > > a way to continue to support it while reducing the mess for other services > > ? > > Reinitiating the sig. channel in some way may not be a bad idea ? > > > > Finally, I must admit I do not understand Chris's comment about making > sure > > the other party is not a GW. > > Why is that so? > > > > > > Boaz Michaely > > VocalTec Communications Ltd. > > +972 (9) 970-7869 > > email: boaz(a)vocaltec.com > > http://people.itu.int/~michaely > > > > > > > > > > > > > > "Paul E. Jones" <paul.jones(a)ties.itu.int> on 02/01/2000 12:04:50 AM > > > > Please respond to "Paul E. Jones" <paul.jones(a)ties.itu.int> > > > > To: "Chris Wayman Purvis" <cwp(a)isdn-comms.co.uk>, "Satya T" > > <satyat(a)MIEL.MOT.COM> > > cc: h323implementors(a)imtc.org (bcc: Boaz Michaely) > > Subject: Re: Closing Q.931 TCP connection.. > > > > > > > > > > Folks, > > > > I would like to second Chris' comments. It really is a very bad idea to > > close the call signaling channel. This might have been important prior to > > H.245 tunneling and Fast Connect, but in my opinion, this just isn't > > necessary any longer. > > > > My chief complaint is that once the channel is closed, there's no > guarantee > > one can re-open it. This is especially true on the receiving end-- the > > called endpoint may not know the call signaling address to which to try to > > re-establish a socket connection, and it cannot assume 1720. Reverse call > > setup may not even be possible, given some network arrangements (including > > the usage of devices to traverse firewalls). > > > > There are several reasons to keep the channel open, too. This gives the > > endpoint the ability to perform supplementary services. If the channel is > > closed, the endpoints lose that functionality-- unless we can guarantee a > > way of re-establishing that channel. > > > > So, my advise to all implementers: never, never close the call signaling > > channel. > > > > Paul > > > > ----- Original Message ----- > > From: "Chris Wayman Purvis" <cwp(a)isdn-comms.co.uk> > > To: "Satya T" <satyat(a)MIEL.MOT.COM> > > Cc: <h323implementors(a)imtc.org> > > Sent: Tuesday, December 21, 1999 8:52 AM > > Subject: Re: Closing Q.931 TCP connection.. > > > > > > > Satya, > > > > > > This is the subject of much current discussion, but the group within ITU > > SG16 > > > discussing robustness. Currently: > > > ReleaseComplete closes the call. > > > Closing the Q.931 TCP connection without ReleaseComplete does not close > > the > > > call if there is a separate active H.245 connection. > > > However, consideration is being given to the possibility of changing > this > > rule, > > > if no implementations can be found that deliberately close the Q.931 TCP > > > connection during a call. > > > > > > I strongly advise against deliberately closing the Q.931 TCP connection > > without > > > terminating the call, but as things currently stand > > > a) you are permitted do so as long as there is no gateway involved in > the > > call > > > (which you may or may not be able to know!!!) > > > b) you should cope with other parties in the call doing this (unless you > > or > > > they are a gateway!!!!!). > > > > > > Regards, > > > Chris > > > > > > Satya T wrote: > > > > > > > > Hi all, > > > > There's a gatekeeper routed call, > > > > and if the GK closes down the Q931 TCP connection, > > > > does it mean the call is closed? Consider the following cases : > > > > > > > > 1. When GK sends RELEASE complete before breaking > > > > down the TCP > > > > 2. When GK does NOT send RELEASE complete before > > > > breaking down TCP > > > > > > > > H.245 connection is established & ON directly between the EPs in > > > > both cases when the Q931 TCP is broken down. > > > > > > > > Is it considered closed in both the scenarios? or only in the former? > > > > > > > > regards > > > > Satya T > > > > > > > > > > > > -------------------------------------------------------------------------- > > > > > > -- > > > Dr Chris Purvis -- Development Manager > > > ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road > > > Winkfield Row, Berkshire. RG42 6LY ENGLAND > > > Phone: +44 1344 899 007 > > > Fax: +44 1344 899 001 > > > > > -------------------------------------------------------------------------- > > -------------------------------------------------------------------------- > - > > ------------------------------ > > Please send E-mail to contact(a)imtc.org <mailto:contact@imtc.org> to > > subscribe or unsubscribe from this list > > ------------------------------ > > -------------------------------------------------------------------------- > - > > > > > > > > > > > > > > --------------------------------------------------------------------------- > ------------------------------ > Please send E-mail to contact(a)imtc.org <mailto:contact@imtc.org> to > subscribe or unsubscribe from this list > ------------------------------ > --------------------------------------------------------------------------- -- Dr Chris Purvis -- Development Manager ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road Winkfield Row, Berkshire. RG42 6LY ENGLAND Phone: +44 1344 899 007 Fax: +44 1344 899 001

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