Re: [H.323-SIP/Internet] The reason.
Many thanks for all the information on this from all sides.
I think Tom Taylor's summary captures best where we are, and what the solution should be, and I agree with him.
If there is a need (which might very well be...) to clean up any "mess" that might have resulted from the SIP vs. H.323 standardization effort, that should be done by more neutral third parties that have more distance to the detailed H.323 and SIP standardization and who concentrate on interoperability such as ETSI TIPHON or IMTC (where development engineers try to figure out in their implementation what was really meant in the standards, and might try to make H.323 an SIP systems peacefully cooperate).
So, this is my contribution to the "Q.13 and Q.14 invitation on how to approach
the work".
Regards, Istvan Sebestyen -------------------------------------------------------------------------- Dr. Istvan Sebestyen Siemens AG, ICN M CS27, Hofmannstr. 51 D-81359 Munich Tel:+49-89-722-47230 Fax:+49-89-722-47713 E-Mail office: istvan.sebestyen@icn.siemens.de; istvan@sebestyen.de E-mail private: istvan_sebestyen@yahoo.com; Siemens Intranet:http://netinfo.icn.siemens.de/es/team/essp/team/essp4 Siemens FTP: ftp://mchhpn006a.mch.pn.siemens.de ---------------------------------------------------------------------------- ----------------
From: Tom-PT Taylor[SMTP:taylor@NORTELNETWORKS.COM] Reply To: Mailing list for parties associated with ITU-T Study Group 16 Sent: Thursday, February 24, 2000 10:34 PM To: ITU-SG16@mailbag.cps.intel.com Subject: Re: [H.323-SIP/Internet] The reason.
I should make one thing clear, as it does not seem to be outside the IETF. There is only one official version of SIP: that presented in RFC 2705. BUT, just as SG 16 works on successive versions of H.323, the IETF is working on the next version of SIP. It is the discussion of what should be in the core specification next time around versus what should be in various extension documents which may be causing the confusion in people's minds. BTW, it seems to me that extensions are roughly the IETF equivalent of ITU-T options.
That said, I agree with Bob that all that came out of the discussion was a feeling that the terms of any such work need to be hammered out, plus a willingness to consider further contributions so long as they don't get too detailed.
Looks to me like this work is going to be done in TIPHON and the interoperability consortia. Neither the IETF nor the ITU-T really seems to want it at this point.
-----Original Message-----From: Callaghan, Robert [SMTP:Robert.Callaghan@ICN.SIEMENS.COM] Sent: Thursday, February 24, 2000 4:10 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: [H.323-SIP/Internet] The reason.
Orit, This is the statement from the Q.14 meeting report: ======= Start 3.8.5.1 D.352 - H.323-SIP Interworking [AT&T, et al]This was presented together with D.413. Comments included: · Concerns about joint development with IETF · Which version of SIP would be used? · Suggest postponing this until the next study period - need to look
at how Q.13 and Q.14 were formulated 4 years ago and see how output compares with phrasing of work in these questions · Activities should include comparing call models, media signaling · Concerns about increased travel - maybe this should not be done in
SG16 · Forming a new question might not be the best answer - this would split the expertise in SG16 again (as Q.13 and Q.14 have moved away from joint sessions) · Need to work from official process of IETF (i.e., use only the IETF equivalent of a Recommendation) · Consider gatekeepers working with TRIP Individuals saw merit in the work. Invite contributions on how to approach
the work. Need to get scenarios for progressing work in a controlled architectural approach. Ms. Levin has volunteered to draft a framework. See additional notes in Q.13 meeting report.
======= End This is the statement in the Q.13 report: ======= Start D.413(2/16) [Canada] - Interworking Between H.323 and SIPNetworks
This calls for the creation of an interoperability question in SG16,that would cover among other things, H.323/SIP interworking.
With regard to both D.352/D.413, it was noted that there are severalversions of SIP, it is hard to start any work to interoperate with SIP as SIP is ill-defined at this point in time. The wisdom of starting a new question near the end of the study period was also questioned. It was also mentioned that a great deal of work needs to be done in terms of defining the procedures and architecture that would apply to this work. One suggestion is that interoperability should be between standards bodies such as the ITU and IETF, and this should be the focus of the work, i.e. that the target is official IETF RFCs and not SIP type documents produced by various other bodies. There were various expressions of support that this should be studied, and contributions related to architectures and priorities are solicited. It was agreed that contributions should address both Q13 and Q14.
======= End I cannot see in these statements any thing representing an agreementas to the work to be performed. Your attached terms of reference were not approved at the working party, which is required, nor in the Question meeting. Without an agreement as to the scope, I do not see how to move the work forward, even if many people see it as valuable. Therefore you paper on terms of reference can be accepted as a contribution to the Osaka meeting for discussion.
I do know that the proposal for a new question was rejected at thequestion level, and not brought forward to the working party or study group level.
Talking to Dale, I know that he wants to start the work with H.225.0Annex G to TRIP. Other items are to follow.
For me one of the problems is the culture clash. I do not feel thatthe ITU should represent itself as SIP experts and I do not accept any IETF person
as an H.323 expert. Therefore the work should be done jointly. No one wants to repeat the process used by H.248, so what is the process to be used?
Bob ------------------------------------------------------------------Robert Callaghan Siemens Information and Communication Networks Tel: +1.561.997.3756 Fax: +1.561.997.3403 Email: Robert.Callaghan@ICN.Siemens.com
-----Original Message-----From: Orit Levin [ mailto:orit@radvision.com] Sent: Thursday, February 24, 2000 2:27 PM To: ITU-SG16@mailbag.cps.intel.com Subject: Re: [H.323-SIP/Internet] The reason.
Hello Sebestyen!There is additional chapter from Q.14 Report with the same meaning, but I am sure it doesn't answer your question. During Geneva meeting additional related aspects were discussed. In my previous mail I was referring to the
attached paper. (You will find references to relevant contributions in this paper.) Currently this paper is one of the opinions and possible directions. We are having this discussion on the list in order to get an understanding
of the work we would like to pursue and prepare contributions for Osaka meeting. 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 orit@radvision.com -----Original Message----- From: Sebestyen Istvan ICN M CS 27 Istvan.Sebestyen@icn.siemens.de To: ITU-SG16@mailbag.cps.intel.com ITU-SG16@mailbag.cps.intel.com; 'Orit
Levin' orit@radvision.com Date: Thursday, February 24, 2000 2:02 PM Subject: RE: [H.323-SIP/Internet] The reason.
>Orit,I am a bit confused on what should be done here. I have only found in
TD-74
(ITU-T SG16 Working Party 2 Report) the following passages:
"D.352(2/16) [Various] - H.323 SIP Interworking
This document calls for a joint ITU-T/IETF study of H.323/SIP
interworking.
D.413(2/16) [Canada] - Interworking Between H.323 and SIP Networks
This calls for the creation of an interoperability question in SG16, that
would cover among other things, H.323/SIP interworking.
With regard to both D.352/D.413, it was noted that there are several versions of SIP, it is hard to start any work to interoperate with SIP as
SIP is ill-defined at this point in time. The wisdom of starting a new question near the end of the study period was also questioned. It was
also
mentioned that a great deal of work needs to be done in terms of defining
the procedures and architecture that would apply to this work. One suggestion is that interoperability should be between standards bodies
such
as the ITU and IETF, and this should be the focus of the work, i.e. that
the
target is official IETF RFCs and not SIP type documents produced by
various
other bodies. There were various expressions of support that this should
be
studied, and contributions related to architectures and priorities are solicited. It was agreed that contributions should address both Q13 and Q14."
Is there anything else as "Mission Statement" for the interim work?
Regards, Istvan
Dr. Istvan Sebestyen Siemens AG, ICN M CS27, Hofmannstr. 51 D-81359 Munich Tel:+49-89-722-47230 Fax:+49-89-722-47713 E-Mail office: istvan.sebestyen@icn.siemens.de; istvan@sebestyen.de E-mail private: istvan_sebestyen@yahoo.com; Siemens Intranet: http://netinfo.icn.siemens.de/es/team/essp/team/essp4 Siemens FTP: ftp://mchhpn006a.mch.pn.siemens.de
--
From: Orit Levin[SMTP:orit@radvision.com] Reply To: Orit Levin Sent: Thursday, February 24, 2000 6:53 PM To: ITU-SG16@mailbag.cps.intel.com Subject: [H.323-SIP/Internet] The reason.
Hi! I would like to highlight the reason of "H.323-XXX" work in ITU-T as described in the initial paper.
H.323 is NOT new to Internet. Internet is evolving and new
specifications
in "IP telephony" area are being defined in IETF. This is a time to consider each one of these specifications to be applied to H.323. If
found
useful from technical point of view (as a kind of Back End Services) or
just as required for interworking purposes (such as H.323-SIP
scenarios),
standard definitions for H.323 should be formulated. These two are connected since the first definitely helps the second.
The written above agenda is a proposal for the work scope. Based on our
discussions, it seems like more then one company would like to see this
work beyond the topic of H.323-SIP interoperability. (forget the name
:-)
) If we agree that standardization is needed for this kind of work, the
only possible way to do it is to participate in ITU-T process (with all
its meaning).
Currently we are in the beginning of the process sorting out topics of
our
interest. I think most of us are aware of the work being done in other organizations. We would like to see experts (including from TIPHON and IETF) presenting their concepts to ITU (starting from the mailing list)
keeping us from repeating their work and being aligned with them.
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 orit@radvision.com
participants (1)
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Sebestyen Istvan ICN M CS 27