[Serusers] How to force proxy instead of forward?

mawali at news.icns.com mawali at news.icns.com
Wed Jun 30 23:44:34 CEST 2004


Hi

I posted the below message a couple of days ago. I want all numbers 
starting with 8 to go to a SIP PSTN gateway. The problem is that neither 
forward() nor relay_to_udp() work through NAT. I want to be able to use 
rtpproxy (or mediaProxy for that matter) for such connections. I see that 
forward() and relay_to_udp() both bypass the nathelper rtpproxy. Anyone 
knows the best way to ensure rtpproxy involvement in this scenario. If 
rtpproxy is not involved, I cannot use the PSTN gateway from NAT'd 
endpoints. There is gotta be a way.

                                /-------------------\
                                | SER (port 5060) + |
      SIP UA <----- NAT ------> |      rtpproxy     |
                                |                   |
                                |   SIP_PSTNGW      |---->PSTN
                                | (* at port 7060)  |
                                \___________________/


Previous post:

Hi

I am trying to send all my calls to a PSTN gateway (asterisk with digium 
cards running on the same machine on 7060). I can use forward, but then I 
cannot use the solution SER provides me by using NAT helper. Consider the 
forwarding script:
     Â	if (uri=~"^sip:[8].*@")
                     {
                      forward(209.7.34.58,7060);
                 }

Here it works fine if I am calling from a public IP, but will not work if 
I am calling from a NATed client since this stateless forwarding will 
take SER out of the picture, and rtpproxy will not be used. I have also 
tried using t_relay_to_udp, but is is doing the same, the below lines are 
still not making SER to proxy the request.

                if (uri=~"^sip:[8].*@")
                {
                     t_relay_to_udp("209.7.34.58","7060");
                      break;
                }

What would be the best way of doing it. I want SER to act as a proxy 
(B2BUA?) between my caller and the PSTN asterisk server. I want to be able 
to use nathelper for this scenario.

Regards







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