I just spoke with Marc Robins who heads up the SIP forum. Marc is on
the left and tells me his forum has two new working/task groups... One
on fax over IP and the other on SIP endpoints.
Max Schroeder is whip of the fax over IP or FoIP group.
The goal of these groups is to increase interoperabilty in fax and
user agents. Expect a best practices document for how to make SIP
devices as easy to connect as a PSTN phone.