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Re: [MMUSIC] Should we put the SCTP max message size in the SDP?

From: Eric Rescorla <ekr@rtfm.com>
Date: Sun, 24 Nov 2013 08:51:35 -0800
Message-ID: <CABcZeBPKDXnCZWNaYQj9Viqw9PgzUFmodqY996M9EhsC5+OPPw@mail.gmail.com>
To: Michael Tuexen <Michael.Tuexen@lurchi.franken.de>
Cc: Martin Thomson <martin.thomson@gmail.com>, "mmusic@ietf.org" <mmusic@ietf.org>, "public-webrtc@w3.org" <public-webrtc@w3.org>, Peter Thatcher <pthatcher@google.com>
On Sun, Nov 24, 2013 at 8:47 AM, Michael Tuexen <
Michael.Tuexen@lurchi.franken.de> wrote:

> On Nov 24, 2013, at 5:15 PM, Eric Rescorla <ekr@rtfm.com> wrote:
>
> > For concreteness, here's what I suggest.
> >
> > - An SDP attribute which indicates the maximum message size that
> >   the endpoint is willing to accept. The other side should assume that
> >   any larger message will be rejected, though there is no requirement
> >   that it do so (just as there is no requirement to behave in any
> >   particular way if an unadvertised RTP PT is received).
> >
> > - If the attribute is not present, the assumption is that there is some
> >   sensible (small) default that matches the behavior of existing
> >   browsers. 64k?
> >
> > - An attribute value of '0' means I will do my best with whatever you
> >   send me, subject to memory capacity, etc.
> >
> > - Proposed name: 'max-message-size'
> I agree with the semantic, but I think 'supported-message-size' describes
> better what you describe above. It is not the maximum, since it is not
> specified
> what happens with larger messages. Don't get me wrong: I like you semantic,
> just find the name a bit misleading.
>

I would be fine with your proposed name.


Why not remove your second point? If the sender wants to limit the size,
> it will signal it in SDP, if it has no limit, it doesn't signal it.
>

Ordinarily I would agree with you, but there are extant implementations
which don't signal so I'm thinking of minimizing failures with them.

-Ekr

Best regards
> Michael
> >
> > -Ekr
> >
> >
> >
> > On Sat, Nov 23, 2013 at 2:54 PM, Martin Thomson <
> martin.thomson@gmail.com> wrote:
> > On 23 November 2013 13:32, Eric Rescorla <ekr@rtfm.com> wrote:
> > > 3. The semantics should be that each side just gets to inform the other
> > > side of their value, not that it's negotiated.
> >
> > This is especially important.  "negotiation" here makes zero sense.
> >
>
>
Received on Sunday, 24 November 2013 16:52:43 UTC

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