xAP enabled SIP proxy?

[Gregg Liming <gregg@xxxxxxxxxxx>]

Hi,

Is anyone aware of any work toward implementing a xAP enabled
(preferably CTI compliant) SIP proxy?

The motivation for the question is that my 2-line hard, SIP phone is
configured to connect to my local (personal) asterisk server and the
other line to an outside SIP server.  I use axc for the local asterisk
server, but don't have any way of getting similar support for calls
placed/accepted to/from the externally connected SIP server.
Presumably, users of "consumer" or "residential" VoIP
plans (e.g.,
Vonage, Voicepulse, etc.) might have similar needs.

In anticipation that the answer to the above question is "no",
does
anyone else have interest (as dev or user)?  I'm also interested in
anyones past experiences with SIP proxies and/or strong feelings as to
whether a true NAT-enabling SIP proxy is needed (e.g.,
http://www.openser.org, http://siproxd.sourceforge.net)
or simply a way
to intercept the SIP commands (i.e., no RTP proxying).  In particular, I
don't really want to develop a SIP proxy when others already exist;
however, some may be overly complex, unwieldy, etc.  Similarly, it would
be most useful if any existing SIP proxy had an existing API/mechanism
of intercepting/accessing the SIP headers.  I would be looking for a
solution that will support NAT-ed SIP phones and not require being run
on the firewall.

Any thoughts, comments, suggestions?

Gregg