Yesterday I got a mail from a client saying they couldn’t reach me. I checked this morning and indeed the phones didn’t ring. I noticed an update, so I did an update on my system and reloaded it after which I could be phoned again. But after an hour or so I checked to see if this was still the case, but no. So I thought “this must have to do with changes I had just done”, reverted the changes and reloaded the system. Again some time went by and again calls weren’t coming in. So it seems like something is wrong, but I can’t seem to find what. I only just now noticed this warning:
[2020-01-24 21:28:23] WARNING[17849] res_pjsip_pubsub.c: No registered subscribe handler for event as-feature-event
It’s repeating every 20 seconds or so. Could this be the case, because I’m not sure what it means. Any other way to find out what is causing the issue?
Try to make an outbound call and see if you can receive an inbound call immediately after that. If you can, most probable a NAT issue if your PBX is behind a NAT device.
I’m not familiar with this specific complaint, but my mind immediately went to ‘Allow transport reload’ on Asterisk SIP Settings, PJSIP tab. Make sure it’s disabled.
I suddenly remembered changing some setting on my Unifi firewall (USG) recently, firewall > conntrack modules > SIP. I will change it back and see what happens.