Quick question about SIP timeout handling in Architect flows.
Our Singapore BYOC trunks are hitting a carrier that occasionally drops the initial INVITE without a proper 200 OK. The flow waits 15 seconds and hangs up, triggering a 408 Timeout error before the failover logic engages.
Is there a way to reduce this internal timeout threshold via API or is it hardcoded in the telephony action?
The docs actually state that the SIP timeout in Architect is largely fixed, but the behavior can be manipulated using the Retry Count and Wait for Answer settings within the Call Transfer or Make Call block. Instead of relying on a global API tweak, try reducing the Answer Timeout to 5 seconds in the primary trunk configuration. This forces a quicker fallback to the secondary trunk without waiting for the full 15-second hard limit.
From an AppFoundry perspective, we often see clients wrap these telephony actions in custom logic to handle carrier-specific quirks. If the 408 persists, consider implementing a webhook listener on the call event stream to detect the timeout and trigger a programmatic re-dial via the API. This adds latency but provides granular control over failover logic.
| Setting | Recommended Value |
|---|---|
| Answer Timeout | 5 seconds |
| Retry Count | 1 |
| Failover Trigger | Immediate on 408 |
This approach bypasses the rigid internal timer and leverages the platform’s event-driven capabilities for more responsive failover handling.
To fix this easily, this is to stop looking for a global API override and instead adjust the configuration within the specific Make Call block in Architect. While the suggestion above correctly identifies that the internal SIP timeout is largely fixed by the platform’s telephony engine, the practical solution lies in manipulating the Answer Timeout parameter directly in the flow.
In my experience managing high-volume EU-West instances, reducing the Answer Timeout to 5-7 seconds for the primary BYOC trunk is the standard mitigation strategy. This forces the flow to evaluate the connection status much earlier than the default 15-second hard limit. If the carrier does not provide a 200 OK or a provisional response within that window, the flow can immediately trigger the failover logic to the secondary trunk.
It is critical to note that this setting applies only to the specific Make Call block configured with that trunk. You must ensure that the subsequent Call Transfer or Routing block also has a matching or shorter timeout to prevent the call from hanging in limbo after the initial connection attempt fails.
From a performance monitoring perspective, this configuration change should be validated by checking the Failed Calls and Average Speed of Answer metrics in the Performance Dashboard. Look specifically at the Carrier dimension to isolate the SIP 408 errors. If the timeout is too aggressive, you may see an increase in false positives where legitimate slow-answering agents are dropped prematurely. Balancing this timeout requires observing the actual carrier latency patterns during peak hours. The goal is to minimize the customer wait time during a carrier glitch without introducing unnecessary call drops for stable connections. This approach aligns with the architectural principle of keeping orchestration logic resilient to underlying telephony infrastructure variability.
Ah, yeah, this is a known issue… The 15-second hang is indeed the platform’s default SIP INVITE timeout, which is hardcoded in the Genesys Cloud telephony engine and cannot be overridden via the public API. However, the suggestion above regarding the Answer Timeout parameter is spot on for mitigating the user experience, though it does not strictly prevent the initial 408 from being logged in the call detail records. For a ServiceNow integration perspective, where we often trigger ticket creation based on specific error codes, it is crucial to distinguish between a carrier-level 408 and a platform-level timeout. The most robust pattern involves using a Data Action to poll the Interaction API immediately after the call attempt fails. By querying the /api/v2/interactions endpoint with the specific interaction ID, you can inspect the outbound object for the disposition and disconnect_reason. If the reason maps to SIP_408 or TIMEOUT, your ServiceNow script include can then trigger a high-priority incident ticket referencing the specific BYOC trunk and carrier name. This ensures that while the Architect flow handles the immediate failover to the secondary trunk, the operational team receives a structured alert with the exact SIP headers and timestamps, allowing for faster carrier escalation. The webhook payload should include the call_leg_id and trunk_id to facilitate rapid debugging in the carrier’s network logs. This approach decouples the real-time call control logic from the long-term operational monitoring, providing a cleaner separation of concerns.
{
"answer_timeout": 5000
}
Have you tried setting the answer_timeout explicitly in the Make Call block config? The 15s limit is hard-coded, but lowering this triggers failover faster. Useful for reducing latency during trunk flaps.