can anyone clarify why our sip trunk logs show 408 request timeout when the servicenow ticket creation webhook succeeds? the architect flow v3.1 triggers the data action on conversation_start. the payload to servicenow rest api returns 201 created within 200ms. however, the sip INVITE fails to the pstn gateway after 5s. gc version 2024-11. is there a known latency issue with concurrent webhook processing blocking sip stack resources?
Have you tried isolating the webhook execution from the SIP signaling path?
Cause:
The 408 timeout indicates the PSTN gateway did not receive a timely response. While the ServiceNow webhook returns 201 quickly, the Architect flow likely waits for the Data Action to complete before proceeding to the SIP invite. If the flow logic is synchronous or lacks proper error handling, it may block the session setup. Additionally, GC resources for concurrent webhook processing can throttle if the queue backs up, impacting SIP stack availability.
Solution:
Refactor the flow to trigger the webhook asynchronously. Use a “Set Variable” action to store the ticket ID locally, then send the payload via a separate, non-blocking Data Action or an external integration engine (like MuleSoft or Azure Logic Apps) that handles the ServiceNow API call. This ensures the SIP invite proceeds immediately.
Alternatively, check your genesyscloud_architect_flow Terraform config. Ensure the Data Action has a reasonable timeout set and is not marked as “blocking” for the call flow.
resource "genesyscloud_architect_flow" "my_flow" {
# Ensure async execution if possible
}
Review the flow logs for any hidden delays in the Data Action execution phase.
Use a fire-and-forget Data Action for the ServiceNow ticket. Set returnOnFailure to false and do not wait for the response.
The SIP stack needs the invite to proceed immediately. Blocking the flow for webhook latency causes the 408. Test this with JMeter to verify the invite goes out before the ticket is created.
The simplest way to resolve this is to decouple the signaling from the api call. set the data action to async execution. this prevents the sip invite from waiting for the servicenow response. we see this often with byoc trunks when flows block on external integrations.
If I remember correctly, this exact synchronization bottleneck was a major headache during our recent migration from Zendesk Talk to Genesys Cloud. In Zendesk, the ticket creation was often handled by background macros that didn’t strictly block the call flow in the same way. When we moved to Genesys, we initially kept the Architect flow synchronous because we wanted to ensure the ServiceNow ticket ID was available for downstream reporting. This caused the SIP INVITE to hang, resulting in those dreaded 408 timeouts with our PSTN provider.
The fix isn’t just about setting the Data Action to async, though that is the primary step. You also need to ensure the flow doesn’t wait for the response object. In the Architect canvas, make sure the Data Action step is configured with returnOnFailure set to false and, crucially, that no subsequent steps depend on the output of that ServiceNow call. If the flow waits for the JSON response, the SIP signaling thread remains occupied.
We switched to a fire-and-forget pattern. The call connects immediately, and the ticket creation happens in the background. For reporting, we now use the conversation ID passed in the webhook payload to link the ServiceNow ticket back to the Genesys interaction later. It’s a bit more work to build the reconciliation script, but it eliminates the latency.
Be careful with rate limiting on the ServiceNow side. If you send a burst of async webhooks, ServiceNow might queue them, which could delay the ticket creation significantly. We added a simple retry logic in our integration middleware to handle this, rather than letting the Genesys flow manage it. This approach mirrors how Zendesk handled high-volume ticket spikes during peak support hours. It keeps the voice path clean and the data path robust.