Freeze one number, one call and the effective controls
Record the dialed telephone number, timestamp and timezone, port state, effective number-routing destination, account registration status, enabled call-divert rules, fallback destination, provider and PBX call identifiers, first provider attempt, PBX edge receipt, delivered called-number form, matched inbound route, answer, media and caller result. Redact credentials and personal numbers.
Classify the first disputed boundary: number ownership, portal route, account registration, provider attempt, edge receipt, DID normalization, PBX match, divert precedence, fallback trigger, answer or media. Do not change them together.
Prove number ownership and the effective portal route
Confirm that the telephone number is present on the intended account and that any port is complete. Export or capture the number’s current routing destination and the time it became effective. Voipfone documents destinations including extensions, voicemail, mobiles, queues, groups and IVRs.
Keep the telephone number separate from the account number used by the published registration examples. A successful REGISTER proves neither number assignment nor the portal destination selected for the failed call.
Follow the provider attempt to the first PBX match
Preserve the provider call identifier, target, source address, request, response or transport error and elapsed time. If the INVITE reaches the edge, retain its Request-URI, To identity, first PBX object or context, normalized DID, first matching inbound route and final destination.
The current FreePBX example uses an account-number DID, while current control-panel pages describe routing individual telephone numbers. Do not assume an identifier or rewrite rule from either page; use the actual delivered request and the selected account configuration.
Evaluate divert precedence before calling it failover
Check Always, When Closed, When Busy, No Answer and PSTN-failover controls independently. An Always route can intentionally prevent PBX delivery. A no-answer path requires a delivered call and an expiry without answer. A busy path requires the applicable busy result. PSTN failover is documented for loss of registration or connectivity, not every rejected or unanswered call.
Record the enabled rule, destination, observed trigger, attempt order, charge owner and final caller treatment. Do not infer a complete timer, retry or restoration contract from a portal label.
Separate answer, media and emergency behavior
After answer, retain both SDP bodies, negotiated codec and DTMF method, RTP endpoints, NAT or firewall decision, bidirectional packet flow and an authorized listening result. A correct number route and PBX match do not prove media.
Do not test emergency calling through an ordinary diagnostic call. Verify the account’s registered emergency address and approved validation process separately, and retain an independently powered alternative route for power or broadband loss.
Correct the earliest mismatch and retest restoration
Change only the demonstrated owner: number assignment, completed port state, portal destination, registration identity, edge policy, PBX context, DID normalization, divert rule or media path. Preserve the prior state and repeat an authorized new-call test for the normal path, the approved fallback condition and return to normal. Record provider attempt, PBX match, answer, two-way audio, clean release and caller treatment separately.
Remove temporary broad routes, packet captures and elevated logging. One successful call does not establish universal availability, capacity, failover timing, emergency behavior or compatibility. No Voipfone account, route, PBX, network path, fallback event or live call was inspected or tested for this diagnostic.
Sources & applicability
Primary references for the technical details above. Operational examples and planning checklists are VoIP.info editorial guidance.
- Voipfone FreePBX configuration guide ↗
- Voipfone inbound routing control ↗
- Voipfone phone-number routing controls ↗
- Voipfone PBX call-divert and PSTN-failover controls ↗
- Voipfone number porting ↗
Examples require adaptation to your topology. No live PBX or hardware testing is claimed.