Freeze one failed call and its effective profile
Record timestamp and timezone, called number, caller identity, provider or PBX Call-ID, expected primary and backups, active number assignment, default profile, Follow the Sun rule, rule timezone, effective interval, actual destination attempted, elapsed time and final response. Do not edit multiple routes while collecting the baseline.
Classify the symptom precisely: no provider attempt; wrong profile; wrong primary; backup skipped; approximately four-second silence with no advance; immediate advance on 503 or busy; 486 treated as terminal; provider attempt but no PBX receipt; PBX receipt followed by local rejection; or answered signaling without media.
Prove the number-to-profile assignment and saved order
Confirm that the number is assigned to the intended routing profile and that any time-based override is active in the expected timezone. Export the primary, second and third route types and addresses exactly as saved. Blank Follow the Sun intervals use the default profile, so the page being edited is not necessarily the profile that owned the failed call.
Validate route syntax by type. IP, DNS A, DNS SRV, PSTN and SIP URI do not have interchangeable address and port semantics. Correct the first assignment or syntax mismatch before changing firewall or PBX logic.
Classify the first destination result
At the intended primary, distinguish a provider-side absence of response from a received SIP response. Preserve the code, reason text, responding address and elapsed time. Commio documents an approximately three-to-four-second wait for no signaling response, immediate advancement for 503 or busy in the route description, and an explicit 486 exception in the same article.
If the observed result differs, do not manufacture silence by dropping replies or map every failure to 503. Confirm the intended terminal-versus-advance behavior with Commio support and retain the case alongside the trace.
Split DNS selection from profile advancement
For DNS A, DNS SRV or SIP URI destinations, preserve the queried name, record type, resolver, answers, priority, weight, TTL and address actually attempted. A retry among records for one destination is not evidence that Commio advanced to the next profile row.
Compare the current account target with current Commio support guidance because public outbound pages contain inconsistent A-record hostname examples. Do not copy an outbound service target into an inbound destination or freeze one resolved edge as the route.
Follow the selected attempt through the PBX
Once Commio attempted the expected target, prove edge arrival with the same Call-ID, source and Request-URI. Then inspect endpoint identification, inbound route match, time conditions, concurrency, final response and answer. A local 486 or 503 can drive provider behavior, so preserve the component that generated it.
After answer, verify SDP addresses, negotiated codec, RTP in both directions and observed audio separately. Do not treat route advancement, 200 signaling or one RTP direction as a successful user outcome.
Correct the first divergence and retest every branch
Change only the first proven mismatch: number assignment, active schedule, route order, destination type, address syntax, DNS data, firewall scope, PBX identification, inbound route or response policy. Repeat the same controlled call and record primary selection, every approved backup, elapsed time, response, PBX result and restoration to the preferred path.
No Commio account, number, routing profile, DNS answer, provider edge, PBX, packet, response, media stream, emergency call or live failover event was inspected or tested. Escalate unexplained response handling with the provider Call-ID, UTC time, profile export and redacted SIP evidence.
Sources & applicability
Primary references for the technical details above. Operational examples and planning checklists are VoIP.info editorial guidance.
- Commio inbound routing profiles ↗
- Commio outbound trunks ↗
- Commio Technical FAQs ↗
- Commio SIP INVITE examples ↗
- Commio outbound routing profiles ↗
- Commio E911 portal workflow ↗
- Commio E911 service overview ↗
- Commio support ticket and escalation guide ↗
Examples require adaptation to your topology. No live PBX or hardware testing is claimed.