If our users close the 3CX app (double tap home button, swipe up on app) and then lock phone using side button on phone - push does not work. If they leave app running or do not lock phone everything works correctly. We are using app version 15.5.18.472. Checked firewall, ports and...
Issue was finally resolved. The inbound DiD number must be in E164 format. I cannot be 100% sure, but I believe I entered the number in E164 format and it was converted to a (xxx) xxx-xxxx format at some point.
Also the SIP Trunk - InBound Parameters setting page was confusing... but this...
Setting up a new system and extension to extension works fine. Outbound calls work but inbound calls fail. Firewall test passed. Using wireshark, I can see the SIP "invite" from Twilio but 3CX responds with Status-Line: SIP/2.0 407 Proxy Authentication Required. I have read the 3CX - Twilio...