Subject: Re: Suggestions...

From: schooler (Eve Schooler)
Date: Wed, 7 Apr 1993 15:39:24 -0700

>Thank you all for the nice discussions at Columbus.  

Ditto.  For those of you who were there and contributed to the 
lively discussion and debate, we appreciated it.  For those of
you remote listeners and contributors of template ideas, thanks
also.  I am also pleased to report that Abel Weinrib of Bellcore has 
agreed to co-chair the confctrl group.

We are readying a version of the minutes for the IETF proceedings, 
a summary of the minutes (for the area leaders), and a revised 
charter for official submission.  It is critical that the charter
be submitted shortly, if the BOF is to be considered for WG status,
and is to have the opportunity to meet in Amsterdam in July.
There are MUCH stricter guidlines for how many times a BOF can meet
these days; either a BOF matures to WG status between one IETF and the
next or it is defunct!

>I would like to
>suggest that we start to produce the following specific docs
>as a first-step to session protocol design and hope that it makes
>sense to the group:
>
>1. A reference model that include our view of the world, ie,
>
>	Application
>	Session control
>	Media agent
>
>It should include descriptions of each of the logical layers and
>general definitions for conference control, session control
>and session control protocol.  We need to make it clear that our
>focus for the short-term is on session control and specify how 
>it fits in the big picture (including RTP, Directory services, etc).

It was proposed and agreed to in the BOFs that we take the minutes and 
turn them into an "issues" document, and include discussion of a
framework (dare I say architecture?!) within which we tackle the
confctrl protocol problem.  

We also stated in the BOF and will restate very clearly in the
charter that our focus in the short-term is on the session protocol.

We can debate to what level of detail we describe the logical layers
that exist at end systems, since again we want to focus in the short-term 
on the between-end-system protocol.  

It was clear during the BOFs that agreed-on definitions are needed for
terms such as conference, connection, session, media agents, etc, to
avoid confusing one another; inevitably the variety of systems
described during the BOFs and in the templates used these terms
differently.

>2. Specifications of session layer services (functions), its interfaces
>to other layers/modules, and components of the session state.
>It is here that we need to define the types of session styles we will
>support (may also describe the ones we will support in the future).
>I think there are three main criteria (or motivations) in differentiating
>among styles:
>
>* different styles abstract different kind of scenarios of conferencing
>  in real life
>* different styles entail different network connectivity requirements
>* different styles entail different synchronization/coordination
>  requirements, thus mechanisms
>
>Defining the styles along these lines will help us indentify components
>needed in the session state and the fields in the packet format of
>session protocol later.
>

We tried during the BOF to avoid discussing the specifics of the 
session state or packet formats.  Instead we were looking to identify
the kinds of functions that are supported by a conference session.
The functional taxonomy begun during the BOF will need refinement.

We cannot tackle all conferencing scenarios, nor can we propose a
single protocol to handle all scenarios.  However, we agreed that it
would be a good exercise to map conversation styles into underlying
networking requirements are (in terms of a confctrl session protocol).
We have the beginnings of a list of conversation styles from the last
IETF minutes.  We also discussed that from a pragmatic standpoint, we
are likely to select one loose style (a la nv, vat, dvc, ivs, etc) and
one tight style (for negotiated and potentially private sessions) and
support them for starters; the question is how loose?  how tight?

>I remember that there were a lot of people expressed willingness to
>do real work, do we have a plan to put these good "brains" and "hands"
>to work?  If you guys (and gals included of course :-)) plan to put out a
>first draft "strawman" or need addtional help, I am here.
>Eve, would you please include the updated charter and schedule when you
>send out the minutes for the BOF?

There is still work to be done before we get to a strawman.   
Here are a list of prioritized tasks:

    ASAP: For IETF Proceedings
	- Slides from BOF ==> send to me
	- Minutes from BOF 
	- Summary of Minutes

    ALSO ASAP: but not required for IETF Proceedings
	- Revised Charter
	- Submit charter to Area Director(s) for official review

    Continuation of BOF discussions:
	- Terminology agreement
	- Issues/Framework document (from minutes)
	- Conversation styles document ==> hone in on which loose 
	  and tight control schemes
	- Functional Taxonomy discussion

Of first priority beyond publishing our meeting in the
IETF proceedings is to submit the charter for official review.  
If you have any concrete comments on the charter now is the time 
to share them.  

I propose we hold a telemeeting via the MBONE to organize 
commitments on the other tasks.  Let me look into availability 
and get back to the list on this...
In the meantime, collect your ideas on the aforementioned tasks
and write them down, or at the very least organize them so that 
you can present them during the upcoming telemeeting.

>Thanks,
>Fengmin

Eve