A conference call was held on Friday, June 15, 2001, between representatives of The CommWorks Corp. and Cisco Systems to begin discussing the requirements for a reliable transport protocol to be used with MoIP, the evaluations of existing protocols against those requirements, and the eventual recommendation of an exisitng (possibly modified) or new protocol for that purpose.
On the call from The CommWorks Corp. were: - Mike Nicholas; and - Jim Renkel.
From Cisco Systems were:
- Herb Wildfeuer; and - Mehryar Garakani.
The call began by discussing the events that led up to the call. It was agreed that the goal of this and future follow-on calls is to develop a joint CommWorks / Cisco Systems contribution to the next meeting of TR-30.1 giving requirements for the MoIP reliable transport mechanism that could be agreed to by the two companies, and possibly an evaluation of existing protocols against these requirements that both companies could also agree to. Requirements and evaluations that could not be agreed to by the two companies would be left for presentation by each company separately. It is understood that there is a desire, once the requirements and possible evaluations have been presented to TIA TR-30.1 and agreed to by them, to have the requirements and possible evaluations presented to the IETF 51 meeting in London, UK, during the week of 8/5/2001. It is also understood that some parties plan to present a draft protocol proposal to that meeting.
It was then agreed that proprietary information previously disclosed in contributions to the ITU-T and TIA groups studying MoIP could be discussed in these conference calls, but no new proprietary information should be first disclosed in these calls.
It was then suggested and agreed that a small "reference model" would be useful in the discussions. The following was agreed to as the refence model, subject to future modification as may be necessary: - The reliable transport issue is bi-directional and symmetric, but is perhaps best addressed by: considering the uni-directional, asymetric case; then combining the uni-directional case with a mirror image of itself to yield the bi-directional case. - The uni-directional case can be represented by this diagram: (See attached file: Reliable transport.vsd).
Discussion then turned to CommWork's contribution PCM01-020, "Transport mechanisms in MoIP operations", to the Nice, FR, rapporteur's meeting of Q11/16, in particular a row by row discussion of Table 1, "Transport mechanism characteristics", on page 8 of that contribution.
It was agreed that the transport protocol must support two-way, unicast sessions. It need not support one-way only or multicast sessions. Jim Renkel will draft requriements statements reflecting this for consideration for inclusion in the joint contribution .
It was agreed that the protocol should be structure preserving, but that this should be described as "packet oriented rather than stream oriented." Mehryar Garakani will draft requirements statements reflecting this for consideration for inclusion in the joint contribution .
In considering the next characteristic, "Structure format discriminating", it was agreed that the issue really being considered here is that of switching / transitioning among VoIP, FoIP, and MoIP "modes" during the course of a call. While no firm agreement was reached on the requirements and mechansim for doing this, the discussion seemed to indicate that the companies were close to agreement. Each company will draft requirements for this to be exchanged via e-mail prior to and discussed at the next conference call.
The next conference call is to be held Tuesday, 6/19/2001, at 10:30 A.M., CDT, 8:30 A.M., PDT.