Hello,

I installed Freeswitch 1.5.7 and am trying to configure it as an telephony application server in an IMS network.  

Here is the high-level signaling flow that I am considering.

1. Two SIP users (User-A and User-B) registered with S-CSCF in the IMS network (not with Freeswitch)

2. User-A makes a voice call to User-B.

3. S-CSCF forwards the SIP INVITE to Freeswitch.

4. Freeswitch acting as a B2BUA changes SDP to anchor the media flow and sends SIP INVITE to User-B back to S-CSCF.

5. SIP 200 OK from User-B follows the same path as INVITE in reverse direction.

I went through the dial-plan documentation and could not figure out whether such a configuration is possible.

Please let me know whether such a configuration is feasible and any broad pointers on how to make it work would be appreciated.

Thanks,

Thomas