Howdy, I've read the draft and overall it looks good. Some minor comments: The examples in section 5 of the draft repeatedly show a Via header as follows: Via: SIP/2.0/TCP bob-TP@xxxxxxxxxxx;branch=z9hG4bK309475a2 This is not a legal Via header format, since the sent-by field cannot contain a '@'. It's meant to be a host or host:port, not a user@host... and more likely a host:port since this is TCP for this example. Also, the examples show a Contact URI host of the domain in the REGISTER request, the same as the target request-URI. While not technically illegal I guess, it's extremely unusual - the purpose of a REGISTER is to register the Contact URI as the reachable target for the Address of Record, and thus the Contact URI should indicate the specific host registering. I suggest changing it to: Contact: <sip:bob-tp@xxxxxxxxxxxxxxxx;transport=tcp>;+sip.fax="t38" Lastly, the example INVITE at the end of section 5 is malformed, both because it's missing mandatory headers, and because the From header has no tag param. -hadriel On Nov 29, 2012, at 9:46 AM, The IESG <iesg-secretary@xxxxxxxx> wrote: > > The IESG has received a request from an individual submitter to consider > the following document: > - 'Indicating Fax over IP Capability in the Session Initiation Protocol > (SIP)' > <draft-hanes-dispatch-fax-capability-06.txt> as Proposed Standard > > The IESG plans to make a decision in the next few weeks, and solicits > final comments on this action. Please send substantive comments to the > ietf@xxxxxxxx mailing lists by 2012-12-27. Exceptionally, comments may be > sent to iesg@xxxxxxxx instead. In either case, please retain the > beginning of the Subject line to allow automated sorting. > > Abstract > > > This document defines and registers with IANA the new 'fax' media > feature tag for use with SIP. Currently, fax calls are > indistinguishable from voice at call initiation. Consequently, fax > calls can be routed to SIP user agents that are not fax capable. A > 'fax' media feature tag implemented in conjunction with caller > preferences allows for more accurate fax call routing. > > > > > The file can be obtained via > http://datatracker.ietf.org/doc/draft-hanes-dispatch-fax-capability/ > > IESG discussion can be tracked via > http://datatracker.ietf.org/doc/draft-hanes-dispatch-fax-capability/ballot/ > > > No IPR declarations have been submitted directly on this I-D. > >