VOIP Over HTTP Tunnel

Joined: Tue 28 of Feb, 2006

Re: VOIP Over HTTP Tunnel

Posted:Sun 28 of Jun, 2009 (13:54 UTC)
If you only have HTTP you're probably out of luck (I doubt you will be able to setup a VoIP-cabable tunnel over real world proxies). Best way out here is to use the proxys "CONNECT"-Feature (RFC 2817). If you have to circumvent only one firewall you may try to find it's weak-spots (maybe 53 UDP is open, and all it takes is to setup you SIP registry to this port).
Joined: Thu 18 of Jun, 2009

VOIP Over HTTP Tunnel

Posted:Thu 18 of Jun, 2009 (06:42 UTC)
Hi All,

I have developed a VOIP Application, that uses PJSip to communicate over SIP channel. This application is working fine until the user is behind the proxy blocking my communication. I have searched from the different forums that there is a way called HTTP Tunneling. I want to ask you about:
- Can we achieve this through HTTP Tunneling, i.e. VOIP over HTTP Tunnel
- If yes then how?

I have looked at one of the forum there was some sample code to communicate through HTTP Tunneling, in which he first make the connection with the proxy server and passes the destination address and port in the headers of the request to the proxy, the proxy in returns establishes the connection and return 200 code. Then there was mentioned to communicate as you want as the proxy will then act as a tunnel and doesn't filters the packet being transfered.

Link: http://www.codeguru.com/cpp/i-n/internet/http/article.php/c6209/

I am bit confused about this approach, as lets suppose we have created the connection with the proxy that internally has connected with my desired destination:
  • Will all the communication performed after that i.e. SIP communication will be through this HTTP Tunnel?
  • If not the how can i tell the PJSip to use this tunnel for communication

Please guide me in this regard. Thanking in advance.