[SR-Users] Error with ACK from SIPML5

Hello All, I have a setup which is SIPML5 -> Kamailio(Websocket) -> Freeswitch. All I am trying to do is initiate a call from SIPML5 and Play a Music file from freeswitch. This works, but the call hangs up after 30 seconds due to ACK timeout from from the SIPML5. What I can see is the SIPML5 from Chrome does send an ACK on websocket, but I see the following error in kamailio syslog: *via_builder(): TCP/TLS connection (id: 0) for WebSocket could not be found* *ERROR: <core> [msg_translator.c:1725]: build_req_buf_from_sip_req(): could not create Via header* *ERROR: <core> [forward.c:607]: forward_request(): ERROR: forward_request: building failed* *ERROR: sl [sl_funcs.c:371]: sl_reply_error(): ERROR: sl_reply_error used: I'm terribly sorry, server error occurred (1/SL)* Can someone help me understand what I am missing here and why kamailio is not able to create a VIA header to forward this request towards freeswitch. I have built a simple config file by following https://gist.github.com/jesusprubio/4066845 as reference. Any help in understanding this is really appreciated. Thanks, --- Jayesh