Voipfone SIP trunks: registration, number routing and fallback evidence

Inventory the account registration and telephone numbers separately

Voipfone’s Asterisk and FreePBX examples register an account number and password against sip.voipfone.net. The FreePBX guide explicitly says the account number used in trunk configuration is not one of the account’s Voipfone telephone numbers. Keep the registrar identity, authentication identity, Contact, account number, each telephone number, port state and routing owner as separate records.

The published examples are chan_sip-era starting points, not a current PJSIP security profile or proof of the fields active on one account. Preserve the raw REGISTER request, challenge, successful response, expiry and effective Contact without exposing credentials.

Treat number routing as a portal control before PBX delivery

Voipfone’s current control-panel documentation says each inbound telephone number can be routed to a selected destination such as an extension, voicemail, mobile, call queue, call group or IVR. That number-level selection is distinct from the account registration and from the PBX rule that handles an INVITE after delivery.

Record the called number, effective portal destination, timestamp, provider call identifier, first provider target, edge receipt, delivered Request-URI and To identity, normalized DID, first matching PBX route and final destination. A registered trunk does not prove that a particular number is assigned, ported, routed or delivered to the intended PBX object.

Keep PBX inbound matching narrower than provider routing

The current FreePBX example creates an inbound route using the Voipfone account number, while the portal documentation describes separately routed telephone numbers. Preserve that source distinction instead of assuming every account delivers the same identifier or format.

Inspect the actual INVITE and the first matching context or inbound route. Caller identity, line-presentation labels, an account number and the dialed telephone number can appear in different fields; none should be silently substituted for the PBX match key. Provider delivery does not prove the extension, queue, group, IVR or voicemail answered.

Model diverts and fallback as explicit downstream controls

Voipfone documents Always, When Busy, No Answer, When Closed and PSTN-failover choices in its call-divert controls. It describes PSTN failover as a destination used when the phone or PBX loses connectivity. These are configured call-routing controls, not evidence that an unobserved outage triggered the intended path.

Record which rule was enabled, its destination, precedence, charge owner, trigger evidence, provider attempt, any PBX response and caller outcome. An Always divert can bypass PBX delivery; a no-answer divert requires a delivered and unanswered attempt; a connectivity fallback is not an established-call survival guarantee.

Trace signaling success and media success independently

After a delivered INVITE, retain the provider source, transport, Request-URI, called-number form, PBX context, matched rule, response sequence and release cause. Then compare both SDP bodies, negotiated codec, RTP endpoints, NAT and firewall decisions, packet flow in both directions and an authorized listening result.

The legacy PBX examples list A-law and RFC2833 DTMF but do not establish a universal current codec, DTMF, TLS, SRTP or packetization contract. A registered account, correct number route or answered extension does not prove two-way media.

Bind porting, emergency and commercial state to dated evidence

A port request, successful registration and portal routing are separate lifecycle records. Preserve the port order, losing-provider acceptance, completion notice, number inventory and authorized acceptance call. For emergency calling, keep each number’s current address, site ownership, approved validation method and an independently powered alternative because Voipfone warns that power or broadband failure can prevent 999 or 112 calls.

Use a dated account record for numbers, extensions, options, usage, support, taxes, credits and diversion charges. No Voipfone service, route, fallback, emergency workflow, price, availability, compatibility or live call was tested for this guide.

Trace one Voipfone number from portal routing outward

Use the Voipfone inbound-number diagnostic to prove number ownership, portal destination, account registration, provider attempt, PBX match, divert precedence and media.