Hello,

 

I’m working on building an RTP Proxy which will allow both regular SIP to SIP transactions and WebRTC to SIP transactions to an Asterisk Server.

 

SIP UAC < ---UDP/SIP --- > Kamailio/RTPEngine Proxy < ---UDP/SIP----- > Asterisk Server

 

AND

 

WebRTC UAC < ---WSS--- > Kamailio/RTPEngine Proxy < ---UDP/SIP----- > Asterisk Server

 

The Kamailio/RTPEngine Proxy is stateless (does not use the tm or registerer modules), and uses the Path module to replace the Route header with a Path header.

 

It works grep for SIP/UDP to SIP/UDP transactions.

 

HOWEVER… It only partially works for WSS to SIP/UDP transactions. The REGISTER/401(Unauthorized), REGISTER/200(OK) transaction works well.

 

When the Asterisk server sends a SIP Options message, I get the following error:

Jun 25 15:47:03 VRTPENGINE kamailio[4953]: INFO: <script>: => OPTIONS < sip:l4umfumh@192.0.2.97;transport=ws;alias=209.141.117.212~59751~6 -> <null> (IP:172.16.0.48:sp)

Jun 25 15:47:03 VRTPENGINE kamailio[4953]: WARNING: <core> [core/msg_translator.c:2815]: via_builder(): TCP/TLS connection (id: 0) for WebSocket could not be found

Jun 25 15:47:03 VRTPENGINE kamailio[4953]: ERROR: <core> [core/msg_translator.c:2003]: build_req_buf_from_sip_req(): could not create Via header

Jun 25 15:47:03 VRTPENGINE kamailio[4953]: ERROR: <core> [core/forward.c:550]: forward_request(): building failed

Jun 25 15:47:03 VRTPENGINE kamailio[4953]: WARNING: <core> [core/receive.c:425]: receive_msg(): error while trying script

 

It appears that the WebSocket corresponding to the WSS leg cannot be located when the request is initiated from the Asterisk Server.

 

Any thoughts on how I can get this to work in the other direction (Asterisk to Kamailio)? I’ve been looking at the WebRTC to SIP Client and Server (https://github.com/havfo/WEBRTC-to-SIP), but that doesn’t quite do what I want it to do (i.e. it appears to act as a registrar server and doesn’t forward REGISTER requests on to another registrar).

 

 

Thanks and regards,

 

Peter H. Manley, Ph.D.

Chief Software Architect

KomBea Corporation

3400 North Ashton Blvd, Suite 470

Lehi, Utah 84043

www.kombea.com

 

Office:+1.801.610.5808

Mobile +1.801.243.7773