[Ballot discuss]
This is a nicely written, easy to understand document. Thank you.

I'd like to discuss some minor clarifications that I think would help
the document more accurately describe what it is about and what it
specifies (as it is a Standards Track document). I'll emphasize that
these are points for discussion rather than issues where I think the
document is unequivocally wrong.

1. (cleared after discussion with Robert Sparks)

2. Are the mandatory fields described in section 8.1 the only fields
that will ever be allowed or is there an expectation that new
mandatory and optional fields might be defined at some point? I ask
because I read the first sentence of section 8.2 to mean that other
fields (TBD in the future) are disallowed from SIP CLF records:

Each SIP CLF record MUST consist of all the mandatory data model
elements outlined in Section 8.1.

It's a small change, but would this replacement be more accurate:

Each SIP CLF record MUST contain all of the mandatory data model
elements outlined in Section 8.1.

3. Another small change, but significant (my opinion, of course!)
would be in the last sentence of the abstract, which led me to believe
the document would be specifying more than it actually does:

We propose a common log file
format for SIP servers that can be used uniformly by user agents,
proxies, registrars, redirect servers as well as back-to-back user
agents.

Does this better describe the contents of the document:

This document describes a framework, including requirements and
analysis of existing, and specifies a data model for development of
a SIP CLF for SIP servers that can be used uniformly by user
agents, proxies, registrars, redirect servers as well as
back-to-back user agents.