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

Re: APC number request for November Rapporteur meeting
by Sakae OKUBO 28 Oct '00

28 Oct '00

Dear Mr. Bougant, Mr. Buckley, Mr. Freundlich, Mr. Skjaeran, Mr. Audet, The following APC numbers have been allocated to your contributions. APC-2003 France Telecom Mobility management protocol in H.323 Annex H APC-2004 Editor (M Buckley) Latest Draft of Annex N of H.323 APC-2005 Lucent Technologies Transport QoS Parameters and Traffic Descriptor for QoS Characterisation in H.323 systems APC-2006 Editor (M Buckley) Latest draft of TIPHON DTS05003 "End to End Quality of Service Control and Signalling in TIPHON Systems" APC-2007 Editor (A Heidermark) Editorial changes to Annex H to H.248 APC-2008 Editor (A Heidermark) Editorial changes to Annex I to H.248 APC-2009 LM Ericsson Use of Call Independent Signalling for Service Control APC-2010 Nortel Networks Use of inband tones in H.323 using special RTP payload types Best regards, Sakae OKUBO *********************************************************** 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 (to be transferred) +81 3 3204 8194 (direct) Fax: +81 3 5287 7287 e-mail: okubo(a)giti.or.jp *********************************************************** ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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[H.323 Mobility:] MDs uploaded
by Jaakko Sundquist 27 Oct '00

27 Oct '00

Hi all, I have uploaded two MDs to the URL: ftp://standard.pictel.com/avc-site/Incoming/Mobility-AHG/ . MD-107 includes refinements to the H.323 Annex H abbreviations and definitions. The original idea was to make the definitions more 3G-like, but as I went through them, I did not find too much that could be made more 3G-like, so the contribution became rather just a general refinement of the terms. Contributions for the 3Gfication are VERY welcome. MD-108 includes a comparison and mapping between the 3GPP all IP netwrok architecture and the H.323 Annex H architecture. Have a nice weekend, everyone. - Jaakko ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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Re: Contribution number
by Sakae OKUBO 27 Oct '00

27 Oct '00

Dear Mr. Audet, Dear Mr. Groves, The following APC numbers have been allocated to your contributions: APC-1996 Nortel Networks Proposed corrections to H.323v4 Annex D on T.38 fax switchover APC-1997 Editor (C Groves) Draft H.248 Implementors' Guide APC-1998 Editor (C Groves) Draft H.248 Annex K - Generic Announcement Package APC-1999 Editor (C Groves) Draft H.248 Annex L - Error Code and Service Change Reason Description APC-2000 Ericsson H.248 Annex x - Load Control Package APC-2001 Ericsson Direction in H.248 annex K APC-2002 Ericsson Signal on Root for H248v2 Best regards, Sakae OKUBO *********************************************************** 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 (to be transferred) +81 3 3204 8194 (direct) Fax: +81 3 5287 7287 e-mail: okubo(a)giti.or.jp *********************************************************** ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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Annex I
by Baese Gero 27 Oct '00

27 Oct '00

Dear Mr. Aronson, since the last meeting in Portland there is a discussion concerning Annex I, unfortunately we haven't heard your opinion as an expert on this area. What do you think about the discussed technical topics as well as the provided test conditions ? Can you please comment on that ? Thank you very much. Best wishes Gero Baese ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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Re: MPEG-4 elementary streams in H.323
by Stephan Wenger 26 Oct '00

26 Oct '00

Gary, Experts, The MPEG-ES I-D is in IESG last call since 10/17. I believe that it is neither to SG16 and certainly not to MPEG to decide of its movement forward. For SG16 it is, however, relevant, that the assignment of an RFC number follows the IESG approval at considerable delay, typically several weeks. Unless someone is pushing the RFC editor really hard, the ES-I-D will not have a RFC number assigned in time for the SG meeting. I don't know what the SG should do regarding the determined code points referencing the draft. If someone wants to stop the progress of the I-D now, the right action would be to announce so, including technical reasons, on the rem-conf reflector. Before doing so I would like you to consider the following: MPEG systems wants, for their own reasons, to promote MPEG systems, not only the media coding schemes. Many (including me) believe that the current system specification cannot be delivered over lossy networks. For that reason, the I-D focusing on the transmission of MPEG systems (SL-draft by Civanlar et. al) will likely move forward as "experimental" only, and not as standards track. I'm not sure that MPEG knows the difference, and I'm also not sure whether we in the ITU allow to normatively reference an experimental RFC. Would be nice to see this clarified. Stephan At 01:50 PM 10/26/2000 -0700, Gary Sullivan wrote: >ITU-T Systems and Video Experts, > >I am at an MPEG meeting in France. There has been a lot of recent >discussion here and in the IETF on how to carry MPEG-4 data on IP >networks. I was asked by some MPEG participants to help explain >and understand the impact of this work on ITU-T SG16. > >My understanding is that the H.323 community has been expecting >an IETF RFC with Proposed Standard status to be approved prior >to the November SG16 meeting sufficient to specify an RTP >packetization format for use in H.323 systems to carry MPEG-4 >video (and perhaps audio) elementary streams. > >However, there are some discussions here at MPEG about how to ensure >that any such specification is adequate not only for the needs of H.323 >but also for MPEG-4 systems as well. > >As a result, it appears that MPEG is poised to recommend tomorrow >that the current Kikuchi-san Internet Draft not be promoted to >Proposed Standard RFC status in the IETF. This seems to mean >that we are unlikely to be able to reach Decision status for this >feature in H.323 in November in SG16. > >The SG16 community needs to understand this unfortunate situation >and its impact on the progress of work for the SG 16 meeting in November. > >Best Wishes, > >Gary Sullivan > >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >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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MPEG-4 elementary streams in H.323
by Gary Sullivan 26 Oct '00

26 Oct '00

ITU-T Systems and Video Experts, I am at an MPEG meeting in France. There has been a lot of recent discussion here and in the IETF on how to carry MPEG-4 data on IP networks. I was asked by some MPEG participants to help explain and understand the impact of this work on ITU-T SG16. My understanding is that the H.323 community has been expecting an IETF RFC with Proposed Standard status to be approved prior to the November SG16 meeting sufficient to specify an RTP packetization format for use in H.323 systems to carry MPEG-4 video (and perhaps audio) elementary streams. However, there are some discussions here at MPEG about how to ensure that any such specification is adequate not only for the needs of H.323 but also for MPEG-4 systems as well. As a result, it appears that MPEG is poised to recommend tomorrow that the current Kikuchi-san Internet Draft not be promoted to Proposed Standard RFC status in the IETF. This seems to mean that we are unlikely to be able to reach Decision status for this feature in H.323 in November in SG16. The SG16 community needs to understand this unfortunate situation and its impact on the progress of work for the SG 16 meeting in November. Best Wishes, Gary Sullivan ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

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Re: Documents uploaded
by Francois Audet 26 Oct '00

26 Oct '00

Bob, I believe in your Annex M.3 draft, it should say H.245 v7 instead of v6 in the ASN.1 in the Summary section since we mandated v7 for H.323v4 at the last meeting. > -----Original Message----- > From: Callaghan, Robert [mailto:Robert.Callaghan@ICN.SIEMENS.COM] > Sent: Thursday, October 26, 2000 11:14 AM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: Documents uploaded > > > The following documents for the November 9-10, 2000 Raporteur > meeting in > Geneva have been uploaded to the PictureTel site: > > APC-1974 Editor (R Callaghan) > H.450.12 - Common Information Additional Network Feature for H.323 > > APC-1975 Editor (R Callaghan) > H.323 Annex M.3 - Tunneling DSS1 in H.323 > > APC-1976 Siemens > H.323 Annex M.3 - Tunneling DSS1 in H.323 - Architecture > > APC-1977 Siemens > Deficiencies of H.225.0 for a native transport of DSS1 > > Bob > > -------------------------------------------------------------- > Robert Callaghan > Siemens Enterprise Networks > 5500 Broken Sound Blvd, Boca Raton, Fl 33487 > Tel: +1 561 923-1756 Fax: +1 561 923-1403 > Email: Robert.Callaghan(a)ICN.Siemens.com > ----------------------------------------------------------------- > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com >

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Documents uploaded
by Callaghan, Robert 26 Oct '00

26 Oct '00

The following documents for the November 9-10, 2000 Raporteur meeting in Geneva have been uploaded to the PictureTel site: APC-1974 Editor (R Callaghan) H.450.12 - Common Information Additional Network Feature for H.323 APC-1975 Editor (R Callaghan) H.323 Annex M.3 - Tunneling DSS1 in H.323 APC-1976 Siemens H.323 Annex M.3 - Tunneling DSS1 in H.323 - Architecture APC-1977 Siemens Deficiencies of H.225.0 for a native transport of DSS1 Bob -------------------------------------------------------------- Robert Callaghan Siemens Enterprise Networks 5500 Broken Sound Blvd, Boca Raton, Fl 33487 Tel: +1 561 923-1756 Fax: +1 561 923-1403 Email: Robert.Callaghan(a)ICN.Siemens.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: Sanity check on Packet Sizes....
by Chip Sharp 26 Oct '00

26 Oct '00

As Brian says, there are several different answers. In reality, the max length IP packet supported is constrained by the MTU (max transmission unit) supported by the host at each end (usually a function of receive buffers) and of the subnets in the path. Since IP is an internetworking protocol, it runs over a number of networking technologies and protocols, each with its own frame or packet size limitation. For example, running IP over an X.25 network (e.g., ISDN D-channel X.25) might limit the MTU size to 128 octets. Ethernet allows 1500 bytes. RFC1191 contains a table of MTU sizes for various subnet technologies and the RFC numbers in which they are defined. I copy the table below (one advantage of having ASCII specs :-). Plateau MTU Comments Reference ------ --- -------- --------- 65535 Official maximum MTU RFC 791 65535 Hyperchannel RFC 1044 65535 32000 Just in case 17914 16Mb IBM Token Ring ref. [6] 17914 8166 IEEE 802.4 RFC 1042 8166 4464 IEEE 802.5 (4Mb max) RFC 1042 4352 FDDI (Revised) RFC 1188 4352 (1%) 2048 Wideband Network RFC 907 2002 IEEE 802.5 (4Mb recommended) RFC 1042 2002 (2%) 1536 Exp. Ethernet Nets RFC 895 1500 Ethernet Networks RFC 894 1500 Point-to-Point (default) RFC 1134 1492 IEEE 802.3 RFC 1042 1492 (3%) 1006 SLIP RFC 1055 1006 ARPANET BBN 1822 1006 576 X.25 Networks RFC 877 544 DEC IP Portal ref. [10] 512 NETBIOS RFC 1088 508 IEEE 802/Source-Rt Bridge RFC 1042 508 ARCNET RFC 1051 508 (13%) 296 Point-to-Point (low delay) RFC 1144 296 68 Official minimum MTU RFC 791 Table 7-1: Common MTUs in the Internet In a general case implementation, I would support at least 1500 bytes MTU sizes. As for your specific application (video), it might not require 1500 byte packets. Supporting some type of Path MTU Discovery (RFC1191 or RFC1981) might be useful to avoid fragmentation since some paths don't support 1500 byte MTUs. For example, many tunneling technologies (GRE, L2TP, IPSEC) reduce the effective packet size. Chip At 10:09 PM 10/25/00 -0400, Rosen, Brian wrote: >There is the "real" answer, and the practical answer. > >The real answer is that depending on what kind of network you are on, >you could see, in theory, packets of up to 64K bytes. 4K bytes can actually >be >seen in some Gig-E systems. Whether you will find a video codec using such >large packets sizes or not is uncertain; I've never seen one. > >It used to be that we thought 1510-odd bytes was the biggest practical >packet you >see on a LAN, but that's no longer the case. There is a lot of code around >that >fails above that 1500 ish number. > >Brian > > > -----Original Message----- > > From: Chris Farmer [mailto:cfarmer@smithmicro.com] > > Sent: Wednesday, October 25, 2000 9:05 PM > > To: ITU-SG16(a)mailbag.cps.intel.com > > Subject: Sanity check on Packet Sizes.... > > > > > > Okay, > > > > I was researching an arcane fact on the theoretical and > > practical sizes for > > RTP packet sizes for > > video conferencing. > > > > What I have come up with is: > > There is specific RFC's about implimenting H.263, H.261, > > G.723, but I'm > > looking for just an overall > > practical size to check input buffer sizes. > > > > RFC 1889 RTP packet structure referes to 768, RFC 791 > > RFC 768 UDP refers to obsolete RFC 760. > > RFC 791 states in the Glossory, > > ARPANET messages max size is about 1012 octets (8096)bits. > > ARPANET packet max size is about 126 octets (1008) bits. > > > > As a client side EP, should I be concerned about the ARPANET > > message size or > > the ARPANET packet size? > > > > RFC 760 states: > > 65,536 octets theoretically, put not practical > > Page 22, every destination should be able to > > receive a datagram > > of 576 octets in one piece or as fragments to be reassembled > > > > so my guess here is 4608 bits max? Or is this too low level > > and there is > > another RFC that I should reference? > > > > Any help in this direction? > > > > Thanks, > > > > > > Christopher B. Farmer > > Software Engineer > > Smith Micro Software, Inc. > > (503) 641-1221 ext 28 > > ====================================================================== > > Daily C\C++ Tidbits at www.EngageUs.com\c > > "Challenges in life are inevitable. Failure is optional" - > > Roger Crawford > > ====================================================================== > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > 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 ------------------------------------------------------------------- Chip Sharp Consulting Engineering Cisco Systems "The best way to pick a lock is with a key." 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: Sanity check on Packet Sizes....
by Roni Even 26 Oct '00

26 Oct '00

Hi, H.225.0 section 6.2.2 mandate the size of video packet not to exceed the MTU size unless the macro block is larger then the MTU. It also say that the frame have to be broken on a GOB or macroblock boundary. The reason is for robustness of information. If a packet is lost then you are losing part of the frame and can still synchronize on the rest of information or replace the missing part. Roni Even -----Original Message----- From: Rosen, Brian [mailto:Brian.Rosen@MARCONI.COM] Sent: Thursday, October 26, 2000 4:09 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Re: Sanity check on Packet Sizes.... There is the "real" answer, and the practical answer. The real answer is that depending on what kind of network you are on, you could see, in theory, packets of up to 64K bytes. 4K bytes can actually be seen in some Gig-E systems. Whether you will find a video codec using such large packets sizes or not is uncertain; I've never seen one. It used to be that we thought 1510-odd bytes was the biggest practical packet you see on a LAN, but that's no longer the case. There is a lot of code around that fails above that 1500 ish number. Brian > -----Original Message----- > From: Chris Farmer [mailto:cfarmer@smithmicro.com] > Sent: Wednesday, October 25, 2000 9:05 PM > To: ITU-SG16(a)mailbag.cps.intel.com > Subject: Sanity check on Packet Sizes.... > > > Okay, > > I was researching an arcane fact on the theoretical and > practical sizes for > RTP packet sizes for > video conferencing. > > What I have come up with is: > There is specific RFC's about implimenting H.263, H.261, > G.723, but I'm > looking for just an overall > practical size to check input buffer sizes. > > RFC 1889 RTP packet structure referes to 768, RFC 791 > RFC 768 UDP refers to obsolete RFC 760. > RFC 791 states in the Glossory, > ARPANET messages max size is about 1012 octets (8096)bits. > ARPANET packet max size is about 126 octets (1008) bits. > > As a client side EP, should I be concerned about the ARPANET > message size or > the ARPANET packet size? > > RFC 760 states: > 65,536 octets theoretically, put not practical > Page 22, every destination should be able to > receive a datagram > of 576 octets in one piece or as fragments to be reassembled > > so my guess here is 4608 bits max? Or is this too low level > and there is > another RFC that I should reference? > > Any help in this direction? > > Thanks, > > > Christopher B. Farmer > Software Engineer > Smith Micro Software, Inc. > (503) 641-1221 ext 28 > ====================================================================== > Daily C\C++ Tidbits at www.EngageUs.com\c > "Challenges in life are inevitable. Failure is optional" - > Roger Crawford > ====================================================================== > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 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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