A SIP Routing Preflight Checklist for an AI Voice Pilot

A SIP routing preflight checklist helps a team discover configuration mismatches before a caller encounters them. The aim is not to certify a route from a settings screen. It is to make the first bounded acceptance call interpretable: if it fails, everyone should know which number, trunk and assistant were intended.

Treat the route as a chain of responsibilities. The business controls the destination number and desired behaviour. The carrier delivers the call. The voice platform admits it and selects a session. An assistant then joins and handles the supported interaction.

Write down the intended route

Create a one-line route description using actual account-owned resources: business number, carrier connection, SIP destination, dispatch configuration and assistant. Include the direction of traffic. Inbound configuration and outbound configuration are not interchangeable simply because they use the same carrier account.

Do not copy credentials into this document. Record the name of the credential set and its owner, plus where authorised operators can manage it. A useful preflight record should be safe to share with the people responsible for the rollout.

If the basic terms are unfamiliar, Burki's BYO SIP guide provides background before the technical owner checks the actual configuration.

Confirm number and account eligibility

Verify that the number is active, belongs to the intended account and supports the direction being tested. Check any account-specific restrictions or required approvals. A number visible in a dashboard is not proof that its current route points at the new assistant.

Also identify the existing destination. If the pilot replaces forwarding or another voice application, save the settings needed to restore it. Make sure somebody can perform that restoration during the test window.

For a hypothetical pilot, use a dedicated test number first. If the business must use its public number, choose a controlled window and a clearly defined rollback trigger rather than improvising after a failure.

Check admission and dispatch separately

An inbound trunk establishes how a call is accepted; dispatch determines where an accepted caller goes. LiveKit documents these as separate configuration concepts. Inbound trunks, dispatch rules.

Ask the technical owner to verify the expected transport, authentication approach, allowed numbers or source restrictions and matching dispatch rule. Then check that the intended assistant is available for the resulting session. A call admitted successfully can still reach the wrong place or wait without an agent.

Avoid opening broad network access as a first troubleshooting step. Compare the observed route with the documented carrier requirements and change only the mismatch you have identified.

Check the time at which the route was last read back. A saved configuration from before a carrier edit may describe an intended route rather than the active one. If another operator is making changes during the pilot, coordinate a brief stable window so the result can be attributed to one known configuration.

Prepare the acceptance evidence

Before dialling, agree on the expected opening and a harmless supported interaction. Record the test time, caller number where appropriate, dialled number and application call identifier. Confirm how to locate the carrier record for the same attempt.

The minimum practical acceptance asks whether the call reached the intended assistant, whether audio was audible in both directions and whether the call ended cleanly. Add keypad or transfer behaviour only when it is required and supported in the chosen mode.

A green configuration check is preflight evidence. A real conversation is route evidence. A completed external action is another layer. Keep those conclusions separate in the release note.

Leave a usable handover

After the test, save the final route, observed result, remaining limits and rollback owner. If a setting changed during diagnosis, update the record rather than leaving the original plan as though it were the deployed state.

Burki's Twilio SIP guide is a useful provider-specific companion where that carrier is relevant. Begin with a written route and one bounded acceptance call; expand only after the evidence matches the service callers will actually use.