SIP 488 Answering Party Not Capable on SG BYOC Trunk

Voice & Telephony
1

Trying to understand why outbound calls via our Singapore BYOC trunk are failing with SIP 488 Answering Party Not Capable. The carrier supports the codec, but the failover logic is not triggering.

  1. Architect flow initiates outbound call.
  2. Platform selects primary BYOC trunk.
  3. Carrier returns 488 instead of 408 or 503.

Is this a codec negotiation mismatch or a carrier-side signaling issue?

2

Ah, yeah, this is a known issue… WFM schedulers don’t touch SIP trunks, so I can’t help with 488 errors, but check if the agent availability status in WFM is syncing correctly to prevent outbound calls to unavailable agents.