Architect IVR Timeout vs BYOC Trunk SIP 408 Handling

Architect & Flows
1

Trying to understand the exact interaction between Architect flow timeouts and SIP registration states on our 15 BYOC trunks. We are seeing a specific pattern in the Singapore region where outbound calls fail with a 408 Request Timeout from the carrier, but the Architect flow continues to wait for 30 seconds before failing over.

The SIP trace shows the 408 arriving within 5 seconds, yet the flow logic does not trigger the error handling path immediately. Is there a specific configuration in the BYOC trunk settings that delays the signal propagation to the Architect engine? We have verified that the timeout settings in the outbound routing policy are set to 10 seconds, which should be sufficient.

The environment is running the latest patch for the Singapore edge nodes. We are not seeing this behavior on the Tokyo trunks, which suggests a regional routing quirk or a carrier-specific SIP stack issue. Any insights on how to force an immediate failover upon receiving a 408 without waiting for the full Architect timeout cycle? We need to reduce the perceived latency for our agents.

Thank you for your help.

2

Make sure you check the JMeter throughput when simulating these outbound scenarios. The 408 delay might not be a SIP config issue but rather GC platform latency under load. I have seen similar hangs during stress tests from Singapore where the WebSocket connection pool gets saturated. Try lowering the concurrent thread count to isolate the carrier response time.

3

It depends, but generally… the Performance Dashboard does not expose raw SIP 408 latency metrics, making it difficult to validate carrier responsiveness without external tools. Be cautious when relying solely on flow timeout configurations for carrier error handling, as the platform may not propagate the SIP failure immediately to the Architect logic.

4

This is actually a known issue. The platform often buffers carrier responses, so you should enable SIP Immediate Failure Propagation in the trunk settings to bypass the default 30-second architect timeout.