Re: [MMUSIC] 1-week WGLC on Section 7.6 (3PCC Considerations) in draft-ietf-mmusic-rfc8843bis-06

[Justin Uberti <[e-mail]>]

On Tue, Nov 23, 2021 at 2:00 AM Christer Holmberg <
[e-mail]> wrote:

> Hi,
>
> >>>1) for some reason, "offer" has been replaced with "Offer" throughout
> the document. This is a minor nit, but seems incorrect to me.
> >>
> >> I did that, because in the previous version we already used "BUNDLE
> Offer", so I thought I'd do it to be consistent.
> >
> > The problem though is that "answer" still is in lowercase so that
> introduces its own inconsistency.
>
> Good catch. I was actually going to change that too, but now realized I
> forgot to.
>
> I have no strong opinion regarding whether we use upper- or lowercase, as
> long as we are consistent.
>
> > Generally I think we should avoid capitalization of common words to
> avoid confusion.
>
> I can change everything to lowercase.
>

Sounds good.

>
> ---
>
> >>>2) The first two paragraphs of 7.6 say similar things and it's not
> clear to me why they both exist. Here is my suggested revision:
> >>
> >> The first paragraph is more general, while the second paragraph
> describes how it is realized in SIP.
> >
> > Understood, but I feel like that intent was not totally clear in the
> current text.
>
> I am mostly fine with your suggested modification.
>
> However, as we don't really talk about "offer semantics" elsewhere in the
> document, perhaps:
>
> "In this situation the endpoint that is not part of a session can receive
> an SDP offer, created as a
> subsequent offer, while expecting an initial offer, as described below."
>
>
That works. It might be easier to understand with the "while expecting an
initial offer" clause first:

"In this situation the endpoint that is not part of a session, while
expecting an initial offer, can receive an SDP offer created as a
subsequent offer, as described below."

But I am fine either way.


> Regards,
>
> Christer
>
>
>
>
>
> OLD:
>
>    In some 3rd Party Call Control (3PCC) scenarios a new session will be
>    established between an endpoint that is currently part of an ongoing
>    session and an endpoint that is currently not part of an ongoing
>    session.  The endpoint that is part of a session will generate a
>    subsequent SDP Offer that will be forwarded to the other endpoint by
>    a 3PCC controller.  The endpoint that is not part of a session will
>    process the Offer as an initial SDP Offer.
>
>    The Session Initiation Protocol (SIP) [
> https://datatracker.ietf.org/doc/html/rfc3261] allows a User Agent
>    Client (UAC) to send a re-INVITE request without an SDP body
>    (sometimes referred to as an empty re-INVITE).  In such cases, the
>    User Agent Server (UAS) will include an SDP Offer in the associated
>    200 (OK) response.  If the UAS is a part of an ongoing SIP session,
>    it will include a subsequent offer in the 200 (OK) response.  The
>    offer will be received by a 3PCC controller (UAC) and then forwarded
>    to another User Agent (UA).  If the UA is not part of an ongoing SIP
>    session, it will process the offer as an initial SDP Offer.
>
> NEW:
>
>    In some 3rd Party Call Control (3PCC) scenarios a new session will be
>    established between an endpoint that is currently part of an ongoing
>    session and an endpoint that is not currently part of an ongoing
>    session.  In this situation the endpoint that is not part of a session
>    can receive SDP with subsequent offer semantics in an initial
>    SDP Offer, as described below.
>
>    The Session Initiation Protocol (SIP) [
> https://datatracker.ietf.org/doc/html/rfc3261] allows a User Agent
>    Client (UAC) to send a re-INVITE request without an SDP body
>    (sometimes referred to as an empty re-INVITE).  In such cases, the
>    User Agent Server (UAS) will include an SDP offer in the associated
>    200 (OK) response, and when the UAS is a part of an ongoing SIP session,
>    this offer will be a subsequent offer. This offer will be received
>    by the 3PCC controller (UAC) and then forwarded to another User Agent
> (UA).
>    When that UA is not part of an ongoing SIP session, as noted above,
>    it will process the offer as an initial SDP Offer.
>
> On Wed, Nov 17, 2021 at 3:16 PM Flemming Andreasen <fandreas=mailto:
> [e-mail]> wrote:
> Greetings MMUSIC
>
> We previously submitted draft-ietf-mmusic-rfc8843bis for publication,
> however subsequently, the issue of 3rd Party Call Control came up and as a
> result of that, Section 7.6 has been updated accordingly.
>
> We are hereby starting a 1-week WGLC on Section 7.6 only in
> draft-ietf-mmusic-rfc8843bis-06.
>
> If you have any comments on Section 7.6, please send those to the document
> authors and the MMUSIC mailing list by Wednesday November 24, 2021. If you
> review it but do not have any comments, please send a note to that effect
> as well.
>
> Thanks
>
> -- Flemming (MMUSIC co-chair)
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