Freeze one order, site, call and failure time
Record UTC and local time, legal customer and site labels, product and order identifiers, access type, portal inventory time, trunk label, assigned numbers, PBX and SBC versions, direction, called and calling values, expected route, first response, answer and audio result. Redact credentials and unnecessary subscriber data.
Preserve last-known-good time and recent order, port, access, firewall, PBX, identity, capacity or location change. Classify the first unexpected boundary instead of changing multiple systems at once.
Prove the enabled service and loaded PBX state
Compare the accepted order and product-specific terms with the portal inventory and the PBX or SBC configuration actually loaded. The reviewed public records do not publish one universal MetTel registrar, authentication model, transport, address range or firewall template, so retrieve account-specific values through the authorized order and support path.
An approved order, enabled portal row, loaded trunk object and accepted provider transaction remain separate. Do not copy credentials or network values from another MetTel product or customer.
Separate capacity, call rate and policy outcomes
For a failed start, preserve the attempt timestamp, active-dialog count, ordered call paths, burst entitlement, calls-per-second window, PBX channel availability, provider response and destination response. MetTel’s public terms name one-call-per-second and traffic-policy boundaries, while the product sheet describes on-demand bursting. Those statements do not establish one order’s capacity or the cause of one rejection.
Retest at a controlled rate only after confirming the authorized window. Do not generate load against production merely to discover a limit.
Trace called number and caller identity independently
For inbound failure, prove number assignment, activation, provider attempt, delivered called value, PBX route match, endpoint alert and answer. For outbound failure, preserve selected trunk, Request-URI, signaling identity, authorization, provider acceptance, downstream presentation and final result.
MetTel requires caller line identity to be authorized. Rewriting a header may change policy compliance without fixing routing, and a completed call from another number does not prove the failing identity is assigned or accepted.
Follow access, signaling, SDP and media without assumptions
Record the ordered Internet or dedicated access, DNS and route result, firewall and NAT state, SIP request and response sequence, SDP offer and answer, selected codec, RTP tuples, packet directions, decoding and listener result for the same authorized call. Preserve where each observation was taken.
G.711 or G.729 in a datasheet does not prove negotiation or two-way audio. A portal state or SIP dialog does not prove media. Do not invent TLS, SRTP, QoS reach, firewall addresses or PBX compatibility from the public product description.
Retest one correction and keep ticket and 911 evidence bounded
Apply one authorized correction, repeat the affected ordinary call and an unaffected control, and retain order, portal, signaling, route, answer, both media directions and hangup evidence. If escalation is required, record the ticket, sanitized artifact, provider finding, action and verified restoration separately.
For location-related work, verify the effective registered address, number, presented identity, callback, PBX and provider route, power, access and independent calling method through approved non-live procedures. Never use a live 911 call as an uncoordinated test. No MetTel service, call, capacity event, media path, outage or emergency result was tested for this diagnostic.
Sources & applicability
Primary references for the technical details above. Operational examples and planning checklists are VoIP.info editorial guidance.
- MetTel — SIP Trunking datasheet, © 2025 ↗
- MetTel — VoIP and SIP Trunking terms, including 911 and traffic-policy boundaries ↗
- MetTel — support, activation, ticket and advanced-services contacts ↗
- MetTel — General Terms applicable to MetTel products ↗
- MetTel — Tariffs and product guides ↗
Examples require adaptation to your topology. No live PBX or hardware testing is claimed.