Stuck on interpreting SIP 488 errors within the Performance dashboard. The queue activity view shows a spike in failures, yet the conversation detail logs indicate successful media establishment for the majority of calls.
The Architect flow is configured for immediate routing with no complex logic. We are running the latest platform version in the EU-West region.
Is this metric reflecting codec negotiation mismatches or a specific BYOC trunk issue? We need to distinguish between platform routing failures and carrier-level rejections.
You should probably look at at the intersection of your trunk configuration and the WFM schedule publishing window. While SIP 488 usually indicates a media negotiation failure, we have seen false positives in the Performance dashboard when the system attempts to route calls during high-load schedule publish events.
The spike you are seeing likely correlates with the time the WFM engine is actively calculating adherence and publishing shifts. During this window, the platform can experience brief resource contention that manifests as 488 errors in the metrics, even if the actual media stream establishes successfully for most agents.
Check the exact timestamp of the spike against your weekly schedule publish job. If they align, this is likely a reporting artifact rather than a codec mismatch. Try staggering the publish job or enabling the “defer metrics update” flag in the WFM settings to see if the error rate drops. This approach has helped us isolate similar discrepancies in our Chicago environment.
It depends, but generally, this discrepancy points to a codec mismatch at the BYOC trunk boundary rather than a platform-side routing error. When I see SIP 488 errors in the Performance dashboard while conversation logs show successful media, the issue is almost always related to the specific codec negotiation between the Genesys Cloud edge and the carrier’s Session Border Controller (SBC).
The dashboard metrics often reflect the initial SIP INVITE rejection before the fallback logic kicks in, whereas the conversation logs record the eventual successful connection after the retry or fallback mechanism engages. To isolate this, you need to examine the detailed SIP trace for the failed attempts. Specifically, look for the Supported and Require headers in the INVITE message. If your trunk is configured to prefer Opus or G.722 but the carrier SBC only supports G.711 (PCMU/PCMA), the initial negotiation will fail with a 488, triggering the platform’s internal retry logic which might then succeed with a compatible codec.
You should verify the codec order in your BYOC trunk configuration under Administration > Telephony > Trunks. Ensure that G.711 is prioritized if your carrier has limited codec support. Additionally, check the rtp-port-range settings; if the carrier is restrictive, a port conflict could also manifest as a 488 before a successful connection on an alternative port.
For a deeper dive into the SIP signaling details, refer to the SIP Trunk Configuration Guide. This documentation outlines the expected header behaviors and how to align your trunk settings with carrier requirements. By aligning the codec preferences and ensuring the SBC allow-listing is correct, you should see the 488 spike disappear from the metrics, reflecting the true success rate of your call flow.