Subject: [Ice] draft-ietf-ice-trickle Section 3

From: Bernard Aboba <[email-masked]>
Date: Mon, 31 Oct 2016 14:02:44 -0700

3 <https://tools.ietf.org/html/draft-ietf-ice-trickle-04#section-3>.
Determining Support for Trickle ICE

   Application protocols that use Trickle ICE should do one of the
   following:

[BA] Is the "should" intended to be a normative statement (e.g. SHOULD)?

If so, I would change this to "To fully support Trickle ICE, applications

SHOULD incorporate one of the following mechanisms to enable implementations

to determine whether Trickle ICE is supported:"

   o  Provide a way for agents to verify support of Trickle ICE prior to
      initiating a session (XMPP's Service Discovery [XEP-0030
<https://tools.ietf.org/html/draft-ietf-ice-trickle-04#ref-XEP-0030>]
is one
      such mechanism).

   o  Make support for Trickle ICE mandatory so that user agents can
      assume support.

   Alternately, for cases where a protocol provides neither of the
   foregoing methods, agents may rely on provisioning/configuration

[BA] I would delete this. Provisioning/configuration is not an

interoperability strategy.  Configuring Agents to assume Trickle

ICE support fails if support is not mandatory and implementation

of Trickle ICE does not help much if implementations are configured

not to use it.

   or use the half trickle procedure described in Section 14
<https://tools.ietf.org/html/draft-ietf-ice-trickle-04#section-14>.

[BA] Would change this to: "Where an application protocol cannot determine

ahead of time whether Trickle ICE is supported, agents MAY utilize the
half trickle procedure

described in Section 14."

   Prior to sending an initial offer, agents using signaling protocols
   that support capabilities discovery can attempt to verify whether or
   not the remote party supports Trickle ICE.  If an agent determines
   that the remote party does not support Trickle ICE, it MUST fall back
   to using Vanilla ICE or abandon the entire session.

[BA] Don't think the term "Vanilla ICE" adds much.  Why not just reference

[RFC5245bis]?

   In application protocols that use SDP, a user agent supporting
   Trickle ICE MUST include a token of "trickle" in the ice-options
   attribute every time it generates an offer or an answer.  This
   enables an agent that receives offers or answers to verify support by
   checking for inclusion of the token.

[BA] This paragraph seems like it belongs in the SIP Trickle ICE draft.

   Dedicated discovery semantics and half trickle are needed only prior
   to session initiation (e.g., when sending the initial offer).  After
   a session is established and Trickle ICE support is confirmed for

   both parties, either agent can use full trickle for subsequent
   offers.