Re: [MMUSIC] Eric Rescorla's No Objection on draft-ietf-mmusic-sdp-bundle-negotiation-51: (with COMMENT)

[Christer Holmberg <[e-mail]>]

Hi,

>>> I have made a few notes of things that I still think are problematic, but I
>>> am clearing my DISCUSS.
>>>
>>>   o  Initial offer: The first offer, within an SDP session (e.g. a SIP
>>>      dialog when the Session Initiation Protocol (SIP) [RFC3261] is
>>>
>>> This appears still not to be resolved. Here is the 3264 definition "
>>> Protocol operation begins when one agent sends an initial offer to
>>> another agent. An offer is initial if it is outside of any context
>>> that may have already been established through the higher layer
>>> protocol." I'm not making this part of my DISCUSS, but I think it's
>>> very confusing and I would strongly urge the AD to address it.
>>>
>>> This is based on the structure that MMUSIC has previously agreed on, and is used in many drafts. 
>>
>> Yes, but it also contradicts the SDP RFC.
>>
>>> The text does explain what “initial offer” means in the context of the document.
>>> 
>>> I am happy to re-visit that discussion in MMUSIC on a generic level, but as far as this document 
>>> is concerned I think we shall keep the currently agreed structure.
>>
>> Ben, Adam? You're the ADs for this.
>
> Ben is the responsible AD here, so I'm deferring to his judgement regarding whether the document can proceed.
> Speaking only as a SIP protocol expert, I agree with EKR that the redefinition of a frequently used RFC-3264-defined 
> term is problematic, and will probably lead to interoperability issues. When readers encounter a term that they 
> believe they understand, it's unlikely that they will notice that it has been redefined to mean something different [1]. 
> I believe that replacing the phrase with something distinctive -- such as "initial bundle offer" -- would alleviate this issue, 
> with no real drawback. I would not think that such a change warrants sending the document back to the WG, but I won't 
> argue against doing so if someone else thinks it does.

I did previously suggest "initial bundle offer", but it did not address Ekr's issue.

It is also important to remember that this affects virtually every SDP attribute we define, unless there are cases where "initial offer" always means the initial offer of a session, i.e., it is not possible to introduce an attribute later in a session.

Regards,

Christer