Solved Bridging: Outbound Calls Failing

[spillihpd]

I am using the 3CX hosted server. I have setup a Master Bridge to connect with a custom PBX that is located on my LAN. I am able to register my PBX with the 3CX server, and I am able to route inbound calls on the 3CX server to a registered extension. Outbound calls through that bridge are failing.

The outbound bridge is setup with a rule prefix of "8". The outbound rule is also setup with this prefix, and points to the bridge. When I do a packet capture on the 3CX server, I see the INVITE coming from my phone, but I never see it send out anything more than a "100 Trying" to the phone, and nothing to my local PBX. When I review the log in verbose mode, everything looks good. The 3CX server identifies the inbound INVITE is meant for the bridge, and it sends on the INVITE, but, I see this:

01/07/2022 11:34:11 AM - Route to L:27.2[Line:10000>>1001] sends Invite-OUT Send Req INVITE from 0.0.0.0:0 tid=650aa03fdc8ced3a Call-ID=sC4Dj2Ctfz-tTSv0Uo3Kzg..: INVITE sip:1001@<censoring IP>:59387;transport=TCP SIP/2.0
Via: SIP/2.0/ ;branch=z9hG4bK-524287-1---650aa03fdc8ced3a;rport
...

Is it possible that the 3CX server is trying to send from an invalid IP address? I do see log messages stating "Default best-route IP is determined as" with a valid IP. And, of course, when I call from my local PBX, the call goes through fine.
The Via header is just wrong as well, missing the transport type (I'm using TCP, but didn't see any success with UDP).

Any guidance is appreciated.

 

[YiannisH_3CX]

Hi @spillihpd

Your logs from the activity look correct, the PBX will add the correct IP address there once the invite is sent out. The VIA is also OK at this stage of the logs.

When looking at the packet capture do you see any traffic to your custom PBX IP? Perhaps the PBX is trying to establish a TCP connection which fails so you do not get an Invite?

You could also try connecting the 2 systems with a SIP Trunk and see if that works.

 

[spillihpd]

Thank you @YiannisH_3CX
I was able to register successfully and call from the PBX through the bridge, so communications were working somewhat. I don't know what exactly changed, but I moved to a different physical location today (completely different city) and everything is now working.

 

[YiannisH_3CX]

Glad to see it is now working. I will set this thread as resolved but please feel free to create a new thread if you face any issues in the future.