BYOC Cloud trunk registration failing — 403 Forbidden from carrier

We are getting a 403 Forbidden error from our carrier when trying to register our BYOC Cloud trunks.

I’m mostly a frontend developer working with the JavaScript Messenger SDK and CSS widget customizations, so the telephony side is completely foreign to me. I checked our deployment snippets and the IDs match what the carrier provided. What could cause a 403 on a SIP trunk?

If your trunks are failing to register, you need to escalate this immediately.

Under MiFID II and Dodd-Frank regulations, our bank is required to maintain highly available communication lines. If our primary BYOC trunks fail and we don’t have a verified, compliant failover path that still supports encryption and recording, we are in direct violation. Are your backup trunks successfully registering, or is the entire org isolated?

A 403 Forbidden from a carrier on a BYOC Cloud trunk usually points to an authentication mismatch rather than a network block.

Check your SIP traces. When Genesys Cloud sends the REGISTER request, the carrier will respond with a 401 Unauthorized challenging it. GC should then send a second REGISTER containing the Digest authentication headers (username and password).

If the carrier responds to that second request with a 403, it means your SIP credentials configured in the GC Trunk settings do not match what the carrier has on file. Verify your IP ACLs and SIP passwords.