Campaign Preview Fails with 408 Timeout on APAC BYOC Trunks

General Discussion
1

Could someone explain why outbound campaign preview calls drop with a 408 Request Timeout when targeting our Singapore-based BYOC trunks? The Architect flow uses standard telephony actions, yet the SBC logs show successful INVITE processing before the Genesys edge disconnects. This issue correlates with peak traffic hours in the Asia/Singapore timezone. We have verified SIP credentials and failover settings. Any insights on latency thresholds would be appreciated.

Thank you.

2

Check your recording export job configurations, as this timeout often stems from conflicting resource allocation during peak hours. While this is a telephony issue, the underlying infrastructure strain affects all API calls in the region. Here is a mitigation strategy:

  1. Verify if any bulk export jobs are running simultaneously. Large metadata exports can saturate the edge node capacity, causing SIP signaling timeouts. Pause non-essential exports during peak APAC hours.
  2. Adjust the timeout parameter in your campaign preview settings. The default might be too aggressive for high-latency BYOC routes. Increase it to 12000ms to allow for SBC negotiation delays.
  3. Review the S3 bucket policy for the recording destination. Ensure there are no latency spikes in writing metadata that block the edge node’s response queue.

This approach prioritizes system stability. Legal discovery exports should be scheduled during off-peak windows to prevent impacting live campaign performance. Monitoring the API health dashboard will confirm if the edge node is the bottleneck.

3

Have you tried adjusting the timeout settings for the telephony action specifically? As someone migrating from Zendesk, I find GC’s strict timeouts can be jarring compared to the more lenient defaults we used to have. The 408 error often stems from the edge waiting for a response that never arrives due to latency, not necessarily a broken connection.

In my experience with APAC trunks, the initial INVITE success is misleading. The real issue is usually the subsequent SDP exchange taking too long. Try increasing the call_timeout parameter in your Architect flow to 15000ms. This gives the Singapore SBC enough breathing room during peak hours without triggering the default 5-second cutoff.

While I am still learning the deeper SIP intricacies, this simple config change resolved similar preview failures for us. It bridges the gap between Zendesk’s flexible trigger logic and GC’s rigid state machine. Definitely worth a quick test before diving into complex routing workarounds.

4

The docs actually state that preview endpoints are not designed for high-concurrency load testing. this 408 timeout is likely because the system expects manual agent interaction for preview calls, which creates a bottleneck in the api throughput. when you hit 100 concurrent calls, the edge drops connections because it cannot maintain the state for unsupervised preview sessions. switch to predictive dialing mode for your jmeter tests. here is a quick config snippet for the outbound campaign settings:

{
 "mode": "PREDICTIVE",
 "dialing_strategy": "SEQUENTIAL",
 "agent_ratio": 1.2
}

this allows the system to handle the call flow without waiting for agent input. also, check your websocket connection limits in ap-southeast-1. if you are hitting the per-tenant cap, the edge will drop the sip signaling. keep the ramp-up gradual to avoid triggering rate limits on the architect endpoints.