Guys, let's please vote for this enhancement (Bug# 37057) at;
Bug 37057 – T.38 Fax Support
Here's another great RFE to vote for, SIP-based click-to-call (not the current "asterisk click-to-call");
Bug 37065 – SIP_based Click-to-Call , and read thread page leading to it;
SIP based Zimlet?