[Freeswitch-users] One way audio problem while using FreeTDM

Hi, In one of the client servers, an old version of FreeSWITCH(FreeSWITCH Version 1.0.head) and a fairly new version of FreeTDM(wanpipe-3.5.28) is being used. Recently a new problem is being observed, where when an incoming call via Sangoma E1 card is redirected to a ring group which rings 3 internal SNOM extensions, and the call is answered on one of them, audio is heard by the caller, but nothing is heard on the callee end. I have captrued the network trace, and I see that there is exchange of RTP packets between the ports specified in the SIP trace (as well as the AUDIO RTP log of freeswitch) Any pointers on how to debug this issue further? Thanks!