Framework for Transcoding with the Session Initiation Protocol (SIP)
draft-ietf-sipping-transc-framework-05

From Gen-ART review by Michael Patton:

...if the document is being changed due to some other
issues, the editors might consider these changes as well.


Minor comments
--------------

I do not believe that all the Normative references are, in fact,
Normative.  In particular, [1] and [8] are only referenced in a "for
example ... could be used" style, which is clearly only Informative.

There is a transcoding case that I think might be a useful example,
but doesn't appear anywhere in the document.  If there is a rewrite,
you may wish to mention it somewhere for additional support.  Perhaps
in the introduction.  The case I'm thinking of is where the two ends
do not support a common bandwidth, perhaps one end only supports high
quality (and therefore high bandwidth) video, but the other end is
bandwidth constrained and requires a different encoding with lower BW
requirements.  For most combinations like this, it would be possible
to have a transcoder that solves the mismatch.  It might even be
offered as a standard option at the ingress to the lower BW portion of
the network.


I note that this document along with references [10] and [11] actually
forms a loosely coupled set, where I understand this document is an
informational overview and the other two are details of the two
approaches.  I applaud this approach, if that's what is intended, but
would like to see that relationship described in this document.  Once
again, a suggestion for better clarity, but not worth holding up the
document if nothing else is being changed.


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   The following editorial issues are noted for the convenience
   of possible copy editors but are not part of the technical review.

Clarity
-------

In Section 3 very near the top of Page 5, you have a reference for
3pcc to reference [7].  Would it also be productive to reference [10]
as well there?  Also, that paragraph has no reference for the bridge
model.  Should [11] be referenced?


Typos
-----

Section 3.1: "This model also allows to invoke" => "This model also
		allows invoking"