This is a weird one. Our location, despite being in a large city on a major road, has only 40 year old copper in the area. No glass, no coax. And the copper (ADSL) is failing. We are trying 5G Cellular for our Internet. It runs great (Rogers) using a vendor-supplied 5G modem by InSeeGo. But we only get 200GB of data per month on that plan, which might be a problem (we are a community theatre with no employees, and no office in the building, so 200GB should handle our monthly volume, but might not). An upgrade to 500GB per month is only $10 month more, the vendor sent us a different modem, a Nokia Fastmile 12.
So I’m testing this new modem at home. I build a new Debian 12 server, installed FreePBX 17 on it, and tested the build with my home Internet connection (cable based, very fast, also Rogers). FPBX works - incoming, outgoing, I can find nothing wrong. No errors in the logs. No problems.
So I shut everything down, plug the fileserver directly into the Nokia modem, and start everything up. All non-VoIP activity works perfectly. Web browsing, email, downloads, YouTube, etc - the bits all flow just fine.
I start up my FPBX server, no errors or complaints, and it registers with our VoIP provider (voip.ms), and shows the same as it does with the cable connection. I call out from the FPBX to my cellphone, it rings, I answer, no audio. I talk into either my cellphone or the handset, nothing comes out the other end. I hangup at either end, and the call ends. I initiate a call from either side, no audio. I direct the incoming call to the IVR or an Announcement, no audio.
I turned on logging and try again, and there is only one new error in the log file (it wasn’t there when I tested over the wired cable connection): This is the first big thing that jumps out at me, so I thought it might provide a clue as to where in the weeds to look next.
ERROR[1658] res_pjsip_header_funcs.c: No headers had been previously added to this session.
I’ve spend hours with Level 2 support at Rogers: They do use CGNAT, they do not block any ports.
In the Nokia modem I’ve tested with no changes (other than LAN IP addressing), with SIP ALG on, and off. No difference. Firewall turned on or off, no difference. I’ve put FPBX in the modem’s DMZ, no difference. The modem does not have a Bridge Mode.
Level 2 Support says the InseeGo modem - which works - and the Nokia 12 modem - which does not work - connects to the same 5G network.
I’m concluding that something somewhere is getting blocked, or not handled correctly, specific to this Nokia modem. But before I return it, does anyone have any inspirations cued by that ERROR 1658 message above?
I do have the asterisk log trace, are there any magic search words (other than ERROR) which I might look for, to assist in finding the needle in this haystack?
Oh. Just one more thing. There is a 401 Unauthorized on the PJSIP log - how would I use that as an anchor to get a hint as to what is going on - look at the exchanges immediately previous, I presume.
I can - but I am trying to avoid - running an A/B comparison doing exactly the same thing on my cable Internet connection, and my Nokia Internet connection, to find any differences. I’m a volunteer at this community theatre, I look a good puzzle, but I don’t get paid for this.
Jim