FreePBX 15 VoIP Integration Fixes

I run FreePBX 15 on a Debian server and need a full tidy-up so the platform behaves reliably and works the way the business requires.

First, the system drops calls or unregisters extensions now and then. I would like the root cause identified (SIP keep-alive, NAT, firewall, transport, or anything else that proves to be the culprit) and a permanent fix applied so the SIP peers stay registered and calls no longer cut out.

Once stability is in place, the default extensions must register flawlessly on Linphone. At the moment Linphone connects, but not always cleanly. A working, repeatable configuration profile for Linphone is part of the deliverable.

The installation then needs to be re-pointed to Telecomsxchange. Instead of my current default trunk, outbound and inbound routes should use the Telecomsxchange credentials, codecs, and dial-plan requirements. CDRs must still show correctly inside FreePBX after the change.

Finally, i need to have A2Billing installed on the server and tie freepbx to A2Billing and so each extension’s credit usage could appear inside Linphone. That means making sure A2Billing talks to FreePBX properly, the billing tables update in real time, and the balance field is exposed to the soft-phone.

Deliverables
• Stable FreePBX 15 (Debian) instance with no random disconnects
• Working Linphone template/profile for my extensions
• Active Telecomsxchange trunk with tested inbound & outbound routing
• A2Billing linked so extension credit shows inside Linphone and decrements per call

Completion is verified when several test calls remain connected beyond 30 minutes, Linphone registers instantly after a restart, calls route through Telecomsxchange, and credit deductions in A2Billing mirror the call duration reported by FreePBX.