SIP 403 Forbidden on BYOC Trunk Failover in APAC

Voice & Telephony
1

Just noticed that failover to secondary carriers for our APAC BYOC trunks is triggering immediate SIP 403 Forbidden errors instead of falling back gracefully. The primary trunk is healthy, but the secondary registration fails with this payload:

{
 "trunk_id": "trk_apac_02",
 "sip_credentials": {
 "username": "acct_secondary",
 "password": "redacted",
 "realm": "genesys.cloud"
 },
 "error_code": 403,
 "reason_phrase": "Forbidden"
}

Has anyone seen realm mismatch issues causing this specific rejection on failover attempts?

2

This looks like a credential mismatch rather than a routing issue. Verify that the secondary trunk’s SIP credentials match the provider’s registration requirements exactly, as a 403 indicates the request is understood but rejected by the destination server. Check the realm and username casing specifically.