Subject: [MMUSIC] Benjamin Kaduk's No Objection on draft-ietf-mmusic-trickle-ice-sip-14: (with COMMENT)

From: Benjamin Kaduk <[email-masked]>
Date: Thu, 29 Mar 2018 14:06:05 -0700

Benjamin Kaduk has entered the following ballot position for
draft-ietf-mmusic-trickle-ice-sip-14: No Objection

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COMMENT:
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Section 5 has (and IIRC other places are similar):

   SIP User Agents (UAs) that support and intend to use trickle ICE are
   required by [I-D.ietf-ice-trickle] to indicate that in their Offers
   and Answers using the attribute "a=ice-options:trickle" and MUST
   include the SIP option-tag "trickle-ice" in a SIP Supported: header
   field.

It's a little strange to me to say that the core trickle spec mandates specifically the
"a=ice-options:trickle" attribute, which is only defined in this document.  The core
spec does mandate some form of indication, but maybe it is more clear to phrase as
something like:

   SIP User Agents (UAs) that support and intend to use trickle ICE are
   required by [I-D.ietf-ice-trickle] to indicate that support in their Offers
   and Answers.  For SIP, this is done using the attribute "a=ice-options:trickle", and
   the SIP option-tag "trickle-ice" MUST be included in a SIP Supported: header
   field.

In the scenario depicted in Figure 10, how is it indicated to Bob that Alice supports
trickle (and should that mechanism be indicated in the figure)?