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Re: H.323 Annex E
by Bell, Bob 25 Nov '98

25 Nov '98

I would second this proposal. The exchange of signalling transport requirements belongs in a CAPS type exchange. -----Original Message----- From: Yoav Medan [mailto:MEDAN@HAIFA.VNET.IBM.COM] Sent: Saturday, November 21, 1998 9:52 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: H.323 Annex E Kishore, IMHO this is more than just an interesting approach. I can see a backward compatibility problem only when endpoints are trying to engage in a peer-to-peer call setup (no GK, thank you). But in a GK routed call setup, why not negotiate UDP or TCP as part of the initial caps exchange? This applies to both endpoint-GK and to GK-GK communications, as you cleverly pointed out. I think we ought to design Internet "Green" (i.e. friendly) protocols that do not flood the network with redundant information unnecessarily. Let's be clever about it rather than smart. Regards Yoav Medan IBM Research, Haifa Lab, Israel Kishore Ramisetty <kish(a)TRILLIUM.COM> on 20-11-98 09:57:50 PM Please respond to Mailing list for parties associated with ITU-T Study Group 16 <ITU-SG16(a)MAILBAG.INTEL.COM> To: ITU-SG16(a)MAILBAG.INTEL.COM cc: (bcc: Yoav Medan/IBMHAIFA) Subject: H.323 Annex E H.323 Annex E proposes using simultaneous (or a little later) TCP and UDP transport connections to provide seamless interoperability with non-Annex E devices. This results in inefficiencies because we now have to transmit two kinds of PDUs for the same call. (Q.931 headers are present for TCP transport and they are absent for UDP). This again has the unfortunate consequence of mandating higher layers to be aware of the transport because upper layers have to deal with duplicates arriving from TCP and UDP connections. (Section E.5.3 para 4 and 5) A simpler solution to this problem is, Annex E compliant end points should register with gatekeeper about their capability of supporting Annex E in RRQ message and gatekeeper propogates this in ACF messages. So, it is easy to determine apriori whether to attempt UDP/TCP connection to the destination end points (because non Annex E devices won't register anything with gatekeepers). This will also require some additions to GK-GK communication so that such kinds of profiles can be communicated across zones. This solution of course requires V3 GKs. If a V3 GK (or GK itself) is absent, then end points could have the option of trying simultaneous connections or simply falling back to TCP. This solution would make sure that going forward to V3 we can get rid of this simultaneous connection establishment procedures. I would like some comments from the group. Thanks, -Kishore. ------------------------------------------------------------------ This message was spam-checked by an evaluation copy of MailShield. See http://www.mailshield.com for more information.

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Rev..3 RE: [wg5-3: 2134] q11h17/apc1457 rev. 2
by Yoshihiro Kikuchi 25 Nov '98

25 Nov '98

Dear Q.11-15 experts, Attached find please the rev.3 of H.245 codepoints for MPEG-4 visual (q11h17/apc1457). The change from rev.2 is only on the default value of the drawingOrder as in the Q.11 meeting report. In the determination version (and in rev.2), the default value of the drawingOrder was 0. It is equal to the minimum value of the drawingOrder. It makes a limitation that a logical channel cannot has the smaller drawingOrder value than that of the logical channel formally opened without indicating drawingOrder. This means that a visual object cannot drawn Behind the visual object associated with the formally opened logical channel with default drawingOrder. I changed the default value to 32768, which is the middle of maximum and minimum values. Please note that the format of rev.3 is quit changed form rev.2 as the delta from H.245 ver.4, but the contents should be the same expect for the above change. If you have any comment on it, please send a message until the end of this week. I will make changes with reflecting all comments, and will send it to the H.245 editor (Mr. Mike Nilsson) next week. Best regards, Yoshihiro -----Original Message----- From: Yoshihiro Kikuchi <kiku(a)eel.rdc.toshiba.co.jp> To: itu-adv-video(a)mack.iterated.com <itu-adv-video(a)mack.iterated.com>; sg16.lbc(a)research.kpn.com <sg16.lbc(a)research.kpn.com> Cc: Yoshihiro Kikuchi <kiku(a)eel.rdc.toshiba.co.jp> Date: Sunday, November 22, 1998 6:47 PM Subject: [wg5-3: 2134] q11h17/apc1457 rev. 2 >Dear Gary, Mike and Q.11-15 experts, > >The attached mail is the one I tried to send last week during the Torino >meeting but not accomplished by a network trouble. I'm sending this >again. I'm also attaching the 2nd. revision of q11h17/apc1457 which is >the >last revision reviewed in the Torino meeting. > >As in the Q.11 meeting report, I should make another revision on the >default value of the drawingOrder. I will send the revised document >soon. > >Best regards, >Yoshihiro > >---- > Yoshihiro Kikuchi > E-mail: kiku(a)eel.rdc.toshiba.co.jp >Research and Development Center TEL: +81 +44 549 2151 >Toshiba Corp. FAX: +81 +44 520 1308 > > >

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FW: Proposed IETF Working Group: MEdia GAteway COntrol (megaco)
by Tom-PT Taylor 24 Nov '98

24 Nov '98

This message has been cross-posted to the Bellcore SGCP list, the ITU SG16 AVC list, and the TIPHON list. All follow-ups to navdec(a)BayNetworks.COM, please. To join the navdec list (probably soon to be renamed megaco), send a message to majordomo(a)baynetworks.com with "subscribe navdec" (no quotes) in the body. At the bottom of this message is the device control working group charter as it currently stands. We can tweak it a bit in the December meeting. I am still working up the agenda and document list for that meeting, which will be on Friday morning, Dec. 11. In the meantime, I would like consideration given to the following: 1. What is the minimum we can put into a first protocol draft? I don't want us to drag this out for two years before we get our first standards-track RFC. Let me put this on the table: the core functionality is connection making and media stream manipulation. Event detection, insertion, and scripting are follow-up items. We might spend some of our time considering what kinds of connections and what kinds of media stream transformations the first protocol RFC should support. If people want to work in parallel on RFCs for specific applications, that's fine. 2. Scott appointed me partly because of my strong interest in trying to keep ETSI TIPHON, ITU-T Study Group 16, and our own working group working together. The other groups are particularly interested in trunking gateways in an H.323 context. SG 16 is interested in multimedia, not just audio. I would like suggestions on how we and they can organize our work to minimize conflict and maximize commonality. 3. Nancy Greene has done a lot of work on architecture and requirements in the past. I propose that she be Document Editor for the architecture and requirements RFC on our work list. More later. Tom Taylor taylor(a)nortelnetworks.com Ph. +1 613 765-4167 > -----Original Message----- > From: Steve Coya [SMTP:scoya@ns.cnri.reston.va.us] > Sent: Monday, November 23, 1998 12:05 PM > To: IETF-Announce > Cc: new-work(a)ietf.org > Subject: Proposed IETF Working Group: MEdia GAteway COntrol (megaco) > > A new IETF working group has been proposed in the Transport Area. > The IESG has not made any determination as yet. > > The following Description was submitted, and is provided for > informational purposes: > > > The working group will develop an informational RFC detailing the > architecture and requirements for controlling Media Gateways from > external control elements such as a Media Gateway Controller. A media > gateway is a network element that provides conversion between the > information carried on telephone circuits and data packets carried over > the Internet or over other IP networks. This work will be done in > consultation with other IETF working groups looking at similar issues. > The working group will also ensure that good information conduits exist > with groups in other standards groups with expertise in the relevant > PSTN technology. Other IETF working groups include PINT, IPTEL and > SIGTRAN. In addition the working group will ensure that reasonable > liaisons exist with similar activities in other standards bodies such as > the ITU-T and ETSI. > > This working group will also define standards track protocol(s) for > controlling media gateways from external control elements such as a > media gateway controller. > > Examples of media gateways are: > > * Trunking gateways that interface between the telephone > network and a Voice over IP network. Such gateways > typically manage a large number of digital virtual circuits. > * Access gateways that provide traditional analog or Primary > Rate (PRI) line interfaces to a Voice over IP network. > * Network Access Servers that can attach a "modem" to a > telephone circuit and provide data access to the > Internet. > > This working group assumes a separation of call control so the call > control "intelligence" is outside the media gateways and handled by a > media gateway controller. This group will NOT work on media gateway > controller to media gateway controller protocols, nor on media gateway > to media gateway protocols. > > Planned output: > > * Architecture & Requirements informational RFC > > * Standards Track RFC for the protocol between a media > gateway controller and a media gateway. > > * Standards Track RFC for the MG and MC MIBs > > * Informational RFC for application programming interface > for the MC to MG protocol

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Re: H.323 Annex E
by Kaynam Hedayat 24 Nov '98

24 Nov '98

Kishore, It was decided at the last meeting that Q.931 headers will be present for UDP call signaling. The absence of Q.931 headers was an oversight by the members of the group. Kaynam Kishore Ramisetty <kish(a)TRILLIUM.COM> on 11/20/98 02:57:50 PM Please respond to Mailing list for parties associated with ITU-T Study Group 16 <ITU-SG16(a)mailbag.cps.intel.com> To: ITU-SG16(a)mailbag.cps.intel.com cc: (bcc: Kaynam Hedayat/PicTel) Subject: H.323 Annex E H.323 Annex E proposes using simultaneous (or a little later) TCP and UDP transport connections to provide seamless interoperability with non-Annex E devices. This results in inefficiencies because we now have to transmit two kinds of PDUs for the same call. (Q.931 headers are present for TCP transport and they are absent for UDP). This again has the unfortunate consequence of mandating higher layers to be aware of the transport because upper layers have to deal with duplicates arriving from TCP and UDP connections. (Section E.5.3 para 4 and 5) A simpler solution to this problem is, Annex E compliant end points should register with gatekeeper about their capability of supporting Annex E in RRQ message and gatekeeper propogates this in ACF messages. So, it is easy to determine apriori whether to attempt UDP/TCP connection to the destination end points (because non Annex E devices won't register anything with gatekeepers). This will also require some additions to GK-GK communication so that such kinds of profiles can be communicated across zones. This solution of course requires V3 GKs. If a V3 GK (or GK itself) is absent, then end points could have the option of trying simultaneous connections or simply falling back to TCP. This solution would make sure that going forward to V3 we can get rid of this simultaneous connection establishment procedures. I would like some comments from the group. Thanks, -Kishore.

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Torino meeting report
by Sakae OKUBO 22 Nov '98

22 Nov '98

Dear Torino meeting participants, The outcome of the closing session last Friday has been placed at the /incoming directory: ftp://standard.pictel.com/avc-site/Incoming/ or http://standard.pictel.com/ftp/avc-site/Incoming TD-12b.doc Genral TD-18b.doc Q.12 TD-19a.doc Q.13 TD-07a.doc Q.14 TD-15a.doc LS to SG15 TD-20a.doc LS to MPEG re MPEG-4 TD-22a.doc LS to MPEG re MPEG-2 These and other materials will later be integrated into APC-1485. PS - Please note that our mailserver(a)giti.or.jp will temporarily be shut down till around 1 AM (GMT) on Tuesday. Please use okubo(a)mxz.meshnet.or.jp if there is any message to me during that time. Best regards, Sakae OKUBO (Mr.) *********************************************************** Waseda Research Center Telecommunications Advancement Organization of Japan (TAO) 5th Floor, Nishi-Waseda Bldg. 1-21-1 Nishi-Waseda, Shinjuku-ku, Tokyo 169-0051 Japan Tel: +81 3 5286 3830 Fax: +81 3 5287 7287 e-mail: okubo(a)giti.or.jp ***********************************************************

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Re: Gateway Decomposition Requirements
by Dale L. Skran 21 Nov '98

21 Nov '98

At 07:54 PM 11/19/98 -0500, Tom-PT Taylor wrote: >I have been told that APC-1466 states enough requirements for the device >control interface A, but that we should have requirements for the signalling It would be more accurate to say that it is a very good start. As mentioned at the meeting, and as discussed below, the terms of reference are not fully reflected in the requirements. >interfaces B, C, and D before committing ourselves to protocol design. I >just don't have the same feeling for detailed requirements in those areas >that I have for interface A. I can only think of two requirements: these >interfaces must >- pass all the signalling content offered to them Not sure what you mean. >- do it quickly and reliably. Of course. I suggest looking at what IPDC does, but this is what comes to mind: B Interface: 1)It must be possible to request that the MGW do H.323 signaling to a specified IP address, which might, for example, be a composed GW. Of course, this is an optional feature. 2)It must be possible to do this call by call, ie. for one call request 323 signaling and for the next not request it. 3)Point 2 strongly suggests that the protocol for B and A should be the same, for example, as in IPDC. C Interface: 1)It must be possible to bring call signaling up to the controller so that signaling can be terminated there (optionally). This suggests a need to map different types of call signaling into a single protocol. Q.931 is an obvious solution. See Ascend's "Reliable Gateway Signaling Protocol" for an example. 2)It must be possible to terminate/generate the Q.931, etc. call signaling on the gateway (optionally). This is equivalent to having the MGW signal 323 on the packet size. This allows a call from a MGW with IMT trunks to talk to a MGW with PRI/T1 trunks under SS7 control. 3)(1) is a kind of tunneling for Q.931, so it is not so clear that this should be the same protcol as A/B. 4)(2) seems like it should be a part of the A/B protcol. X requirements(common requirements on A/B/C): 1)A/B/C signaling must all travel over the same data network to the MGW. 2)It must be possible to use both UDP and TCP 3)Either the protocol is Message/ACK or we must use a reliable UDP like Annex E. 4)Given the similiarity of B/C to A, all should use a similar message format, the same ports, etc. to ease implementation. Note that both B/C parts are probably optional, but they are part of the same protocol as A. The only exception is the case where you want to put SCN call signaling(Q.931, FAS SS7) in the controller, and you need to tunnel it up. This stuff might be tunneled through the A/B/C protocol, or it might be a separate protocol/port, i.e. Q.931 on Annex E with a different port. 5)Part of the A/B/C message set must include an MGW cap set so the controller knows what to expect As noted at the meeting, you need to reflect the terms of reference in the A requirements. A couple of obvious ones: A Interface 1)Must include video/data (i.e. consider the possibility of incoming H.320/H.324 calls). 2)Must not duplicate H.323 functions, eg. cap exchange, conference management, etc. 3)Must be elemental. This goes along with (2). cap exchange is not an elemental function. 4)Must be suitable for connecting an MC (MultiPoint Controller) to an MP (Media Processer) as defined in H.323. This implies a need for elemental conferencing primatives, but broken out by media stream, ie. data MP, voice MP, video MP. I'm sure there is more that could be added by a careful review of the terms of reference. Dale Skran Rapporteur, Q13 WP2 SG16 ITU-T > >Can anyone get us down to another level of detail? > >Tom Taylor >E-mail: taylor(a)nortelnetworks.com (internally Tom-PT Taylor) >Tel.: +1 613 765 4167 (internally 395-4167) >FAX: +1 613 763 7236 (internally 393-7236) >

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Re: H.323 Annex E
by Yoav Medan 21 Nov '98

21 Nov '98

Kishore, IMHO this is more than just an interesting approach. I can see a backward compatibility problem only when endpoints are trying to engage in a peer-to-peer call setup (no GK, thank you). But in a GK routed call setup, why not negotiate UDP or TCP as part of the initial caps exchange? This applies to both endpoint-GK and to GK-GK communications, as you cleverly pointed out. I think we ought to design Internet "Green" (i.e. friendly) protocols that do not flood the network with redundant information unnecessarily. Let's be clever about it rather than smart. Regards Yoav Medan IBM Research, Haifa Lab, Israel Kishore Ramisetty <kish(a)TRILLIUM.COM> on 20-11-98 09:57:50 PM Please respond to Mailing list for parties associated with ITU-T Study Group 16 <ITU-SG16(a)MAILBAG.INTEL.COM> To: ITU-SG16(a)MAILBAG.INTEL.COM cc: (bcc: Yoav Medan/IBMHAIFA) Subject: H.323 Annex E H.323 Annex E proposes using simultaneous (or a little later) TCP and UDP transport connections to provide seamless interoperability with non-Annex E devices. This results in inefficiencies because we now have to transmit two kinds of PDUs for the same call. (Q.931 headers are present for TCP transport and they are absent for UDP). This again has the unfortunate consequence of mandating higher layers to be aware of the transport because upper layers have to deal with duplicates arriving from TCP and UDP connections. (Section E.5.3 para 4 and 5) A simpler solution to this problem is, Annex E compliant end points should register with gatekeeper about their capability of supporting Annex E in RRQ message and gatekeeper propogates this in ACF messages. So, it is easy to determine apriori whether to attempt UDP/TCP connection to the destination end points (because non Annex E devices won't register anything with gatekeepers). This will also require some additions to GK-GK communication so that such kinds of profiles can be communicated across zones. This solution of course requires V3 GKs. If a V3 GK (or GK itself) is absent, then end points could have the option of trying simultaneous connections or simply falling back to TCP. This solution would make sure that going forward to V3 we can get rid of this simultaneous connection establishment procedures. I would like some comments from the group. Thanks, -Kishore.

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H.323 Annex E
by Kishore Ramisetty 20 Nov '98

20 Nov '98

H.323 Annex E proposes using simultaneous (or a little later) TCP and UDP transport connections to provide seamless interoperability with non-Annex E devices. This results in inefficiencies because we now have to transmit two kinds of PDUs for the same call. (Q.931 headers are present for TCP transport and they are absent for UDP). This again has the unfortunate consequence of mandating higher layers to be aware of the transport because upper layers have to deal with duplicates arriving from TCP and UDP connections. (Section E.5.3 para 4 and 5) A simpler solution to this problem is, Annex E compliant end points should register with gatekeeper about their capability of supporting Annex E in RRQ message and gatekeeper propogates this in ACF messages. So, it is easy to determine apriori whether to attempt UDP/TCP connection to the destination end points (because non Annex E devices won't register anything with gatekeepers). This will also require some additions to GK-GK communication so that such kinds of profiles can be communicated across zones. This solution of course requires V3 GKs. If a V3 GK (or GK itself) is absent, then end points could have the option of trying simultaneous connections or simply falling back to TCP. This solution would make sure that going forward to V3 we can get rid of this simultaneous connection establishment procedures. I would like some comments from the group. Thanks, -Kishore.

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signoff itu-g16
by Staffan Olsén 20 Nov '98

20 Nov '98

signoff itu-g16

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Gateway Decomposition Requirements
by Tom-PT Taylor 19 Nov '98

19 Nov '98

I have been told that APC-1466 states enough requirements for the device control interface A, but that we should have requirements for the signalling interfaces B, C, and D before committing ourselves to protocol design. I just don't have the same feeling for detailed requirements in those areas that I have for interface A. I can only think of two requirements: these interfaces must - pass all the signalling content offered to them - do it quickly and reliably. Can anyone get us down to another level of detail? Tom Taylor E-mail: taylor(a)nortelnetworks.com (internally Tom-PT Taylor) Tel.: +1 613 765 4167 (internally 395-4167) FAX: +1 613 763 7236 (internally 393-7236)

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