Subject: [MMUSIC] Fwd: SDP review of draft-ietf-avtext-rtp-stream-pause-07

From: Paul Kyzivat <[email-masked]>
Date: Wed, 10 Jun 2015 14:21:04 -0400

FYI

-------- Forwarded Message --------
Subject: SDP review of draft-ietf-avtext-rtp-stream-pause-07
Date: Wed, 10 Jun 2015 13:15:55 -0400
From: Paul Kyzivat <[email-masked]>
To: [email-masked], [email-masked]
CC: SDP Directorate <[email-masked]>

I am the assigned SDP directorate reviewer for this draft.
For background on the SDP directorate, please see the FAQ at
http://www.ietf.org/iesg/directorate/sdp.html

Please wait for direction from your document shepherd or AD before
posting a new version of the draft.

Summary:

The SDP aspects of this draft are well written and clear. In my opinion
it *can* be published in this form.

However, I do have concern about one aspect - that the manner of
configuring the supported options of this feature is obscure and
confusing. (This is of course a matter of taste.)

Details:

I have concerns about the way the configuration of options is specified
using a numeric value. I can see how that might be reasonable if the
numbers represented a pure hierarchy. But that seems not to be the case.
The rules for valid answers are quite complex. (It isn't something that
can be easily remembered.) This is because each number represents a
particular combination of semi-independent properties, each of which has
separate rules for answers vs. offers.

It seems to me that it would be better to configure these distinct
properties independently. Perhaps just declare each of
{PAUSE,RESUME,PAUSED,REFUSED} that can be sent and received. (And for
convenience, perhaps some extra keywords for common combinations. (E.g.
"all".) Then the rules for valid answers for a given offer would be easy
to state and understand.

	Thanks,
	Paul Kyzivat, for the SDP Directorate