VoIP Mailing List Archives

[juanma.v82 at gmail.com]

Hi,

I'm trying to use the Freeswitch as a proxy (I know that is not designed for that, but I really need to do it in this way), here is my config:

Endpoint 1<-> FS A-<->FS B<->FS A<->Endpoint 2

 * Both Endpoints are registered in FS A how is acting as a proxy and registrar.
 * FS B  only sends back the Invite to FS A in order to reach Endpoint 2.
 * Both FS have a public IP
 * FS A Only handles SIP messages
 * FS B Handles RTP (Also SIP)

My objetive is to keep the signaling in FS A and the RTP in FS B so basically FS A will work as a registrar.

So far I've been able to succesfully do it if both endpoint are not nated, how ever I do need to do it in a Natted sceneario too, for what I have been sniffing the problem is that in the INVITE, the SDP is sending the internal IP instead of the external.

I've tried to change the switch_r_sdp and switch_l_sdp but I'm not quite sure if I'm doing the correct config of the switch (late_codec_negotiation)

If anyone could give a tip or a sample of how can I change the INVITE messages I will appreciate.

Thanks in advance
Regards

[brian at freeswitch.org]

Juan, Can you explain your situation a little better you seem to have breezed over the critical details. Also you should enable STUN on your endpoints and not depend on your Registrar to overcome nat issues since its not its job.


/b

On May 11, 2009, at 10:03 PM, Juan Manuel Vicente wrote:

[juanma.v82 at gmail.com]

Brian,

thanks for your reply

I going to try to explain better my problem. I will use examples to do this task.

Scenario A:

Endpoint 1 <--(sip,rtp)--> FS <--(sip,rtp)--> Endpoint 2
* Endpoint 1 is nated.
* Endpoint 2 is not nated
* Endpoint 1 is sending wrong SDP info, sending local IP instead of public IP (switch_r_sdp). but FS can fix this problem with  <variable name="sip-force-contact" value="NDLB-connectile-dysfunction"/>


the switch_r_sdp in this scenario is:


"[v=0
o=- 3 2 IN IP4 10.0.100.21
s=CounterPath X-Lite 3.0
c=IN IP4 10.0.100.21
t=0 0
m=audio 7208 RTP/AVP 100 106 0 105 98 8 3 101
a=rtpmap:100 SPEEX/16000
a=rtpmap:106 SPEEX-FEC/16000
a=rtpmap:105 SPEEX-FEC/8000
a=rtpmap:98 iLBC/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=alt:1 1 : rnYgTtVR uOhvAtG7 10.0.100.21 7208
]"


Scenario B:


SIP:
Endpoint 1 <--(sip)--> FS A <--(sip)--> Endpoint 2


RTP


Endpoint 1 <--(rtp)--> FS A <--(rtp)--> Endpoint 2



* Endpoint 1 is nated.
* Endpoint 2 is not nated

* Fs is configured with <action application="set" data="bypass_media=true"/>


the switch_r_sdp in this scenario is:


"[v=0
o=- 3 2 IN IP4 10.0.100.21
s=CounterPath X-Lite 3.0
c=IN IP4 10.0.100.21
t=0 0
m=audio 7208 RTP/AVP 100 106 0 105 98 8 3 101
a=rtpmap:100 SPEEX/16000
a=rtpmap:106 SPEEX-FEC/16000
a=rtpmap:105 SPEEX-FEC/8000
a=rtpmap:98 iLBC/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=alt:1 1 : rnYgTtVR uOhvAtG7 10.0.100.21 7208
]"

 
But it is wrong, the correct one must be:


[v=0
o=- 3 2 IN IP4 200.49.24.35
s=CounterPath X-Lite 3.0
c=IN IP4 200.49.24.35
t=0 0
m=audio 63936 RTP/AVP 100 106 0 105 98 8 3 101
a=rtpmap:100 SPEEX/16000
a=rtpmap:106 SPEEX-FEC/16000
a=rtpmap:105 SPEEX-FEC/8000
a=rtpmap:98 iLBC/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=alt:1 2 : CtEyvKrr I3ZLmyBD 10.0.100.21 63936
a=alt:2 1 : 6JO5oo5+ hWtLJ+lx 200.49.24.35 63936
]



To have a correct one I had to configure stun in the endpoint, but the problem is my infrastructure is close to 1000 Endpoints and in some cases I cant reach then to configure properly. 


There any way to fix switch_r_sdp? I can use Opensips or similar SIP proxy but this can add another possible point to failure, and the issue is quite simple.


Thanks in Advance.

On Tue, May 12, 2009 at 12:11 AM, Brian West <brian@freeswitch.org (brian@freeswitch.org)> wrote: