Could someone explain why our primary IVR flow is consistently failing to establish outbound calls via our AP-Southeast-1 BYOC trunks? The issue manifests specifically when the Architect flow attempts to initiate a SIP INVITE to the carrier gateway. We are seeing a rapid failure sequence where the platform sends the INVITE but receives no 100 Trying response before timing out. This happens across all 15 trunks, suggesting a regional edge configuration issue rather than a single carrier fault. The flow logic is standard: it collects digits, validates the number, and then executes a ‘Make Outbound Call’ block with a 30-second timeout. Despite verifying that the SIP credentials and outbound routing rules are correct, the calls drop immediately. The error log from the Architect trace shows the following:
[2023-10-27T08:15:42Z] ERROR: Outbound call initiation failed.
Reason: 408 Request Timeout.
TrunkId: trunk_apse1_byoc_01.
Carrier: Singtel Business.
We have checked the carrier side, and they confirm no packets are arriving at their SBCs. Has anyone encountered similar latency issues with the AP-Southeast-1 edge nodes recently? We suspect a potential DNS resolution delay or a firewall rule blocking the initial handshake.