Freeze one number, one caller and the effective rule set
Record the dialed DID, timestamp and timezone, incoming service, intended 1777 extension, registration Contact, direct DID Forward state and target, applicable Call Treatments and order, Network Down Forward destination, provider and PBX identifiers, edge receipt, answer, media, caller result and both billing legs when forwarding occurs. Redact credentials and personal numbers.
Do not reset the extension password, recreate the DID or edit several treatments at once. Preserve the state that explains why this call followed its actual path.
Check direct DID Forward before lower-priority treatments
Export the DID Forward configured on the affected number. If it is active, compare its PSTN, Callcentric account, SIP URI, IP or fax target with the observed result. Callcentric expressly states that DID Forward rules take higher priority than Call Treatments.
A network-down rule can therefore be correctly configured yet never evaluated. Disable or change the direct forward only when the intended precedence is documented and the previous target can be restored.
Prove registration and normal PBX delivery independently
Verify the selected 1777 extension, registrar domain, successful binding and current Contact. Then place an authorized normal inbound call with higher-priority forwarding absent and preserve the provider attempt, customer-edge INVITE, PBX identification, called-number form, first route, answer and media.
A registered extension is not proof that this DID targets it. A successful PBX call is not proof that Network Down Forward will activate under a later failure.
Observe the provider-defined network-down decision
Create one approved, bounded condition that is safe for the site and retain the last known registration, PBX reachability, provider attempt or absence, elapsed time, selected treatment and forwarded destination. Stop if the test threatens emergency access or unrelated calls.
The public page says the feature applies when the Internet connection is down but does not publish one universal health signal, SIP-response list, timer, retry count or restoration interval. Escalate with exact identifiers rather than declaring the rule broken from one unproved condition.
Trace and price the forwarded leg separately
When forwarding occurs, retain the incoming leg and the new outgoing leg, destination, plan, answer, caller identity, media and release. Callcentric says the outgoing leg consumes included minutes or per-minute service according to the active outgoing plan, while the incoming leg follows its own product.
A ringing or answered mobile proves the new leg, not that the original PBX was unreachable for the intended reason. Confirm the actual account record and bill before representing the feature as cost-free or universally available.
Correct the earliest mismatch and retest restoration
Change only the demonstrated owner: direct DID Forward, Call Treatment scope or order, extension binding, PBX route, forwarded number or outgoing plan. Repeat the normal path, approved network-down condition, forwarded answer and two-way media, then restore connectivity and prove the next new call returns to the PBX.
Remove temporary captures and test rules. A completed sequence does not establish active-call survival, emergency behavior, capacity, pricing, availability or compatibility outside the tested account state. No Callcentric account, rule, PBX, bill, network path or 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.
- Callcentric SIP trunking ↗
- Callcentric registration credentials ↗
- Callcentric DID forwarding ↗
- Callcentric DID-forward precedence ↗
- Callcentric network-down forward ↗
- Callcentric forwarded-call billing ↗
Examples require adaptation to your topology. No live PBX or hardware testing is claimed.