Can't get this integration done

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1

Telnyx inbound calls returning SIP 486 User Busy. Number +19729440992 imported as custom telephony. Agent is assigned. FQDN is sip.retellai.com:5060, A record, UDP transport, +E.164 format. Calls never show in call history. Please help.

2

Hello @raasikh.business your Telnyx configuration has two issues :

  1. DNS record type: Should be SRV, not A record, for sip.retellai.com (omit the :5060 port).

  2. Transport: Should be TCP (recommended over UDP for reliability).

Also confirm:

  • Number format: +E.164 ✓

  • Codecs: G722, G711U, G711A

  • The number is moved to the Elastic SIP Trunk, and that trunk’s outbound voice profile is correctly assigned

The SIP 486 typically indicates the inbound call isn’t matching/routing properly — fixing the SRV record and TCP transport should resolve it. Since calls aren’t appearing in call history at all, the call isn’t reaching Retell’s routing.

See our guide on this ( Telnyx - Retell AI )

Thank You