Looking for advice on handling SIP 488 responses when failover triggers from our primary carrier to backup Carrier B. The Genesys Cloud v2.0 outbound campaign drops the call immediately upon receiving the 488 from the SIP trunk, rather than retrying or falling through to the next configured route. Is there a specific header mismatch or codec negotiation issue common with this carrier that needs adjustment in the BYOC trunk settings?
You might want to check at the codec negotiation settings in your BYOC trunk configuration. The SIP 488 error often stems from a mismatch between the offered codecs in the INVITE and what Carrier B actually supports, especially during failover where the session parameters might reset or differ from the primary carrier. Genesys Cloud defaults to a specific order, but if Carrier B rejects that list, the call drops instead of falling back. Ensuring the trunk explicitly lists only the codecs supported by both carriers can prevent this silent failure. Here is a sample configuration snippet for the trunk settings to enforce strict codec matching:
{
"codecOrder": ["PCMU", "PCMA"],
"strictCodecNegotiation": true,
"sipHeaders": {
"X-Genesys-Codec-Priority": "high"
}
}
Check if Carrier B supports these specific codecs in the same order.
If I recall correctly, the SIP 488 issue during failover is often less about codec negotiation and more about how the outbound dialer interprets transient carrier errors. While checking codec alignment is a solid first step, forcing a strict codec list can sometimes break compatibility with other carriers in the rotation. It is worth verifying if the error persists across different campaign groups to rule out a specific trunk configuration quirk.
The real risk here involves schedule adherence metrics. When calls drop unexpectedly during failover, agents might log these as abandoned or missed interactions, skewing adherence reports. This creates noise in the WFM data that makes it harder to predict staffing needs accurately. Ensure that any retry logic does not inadvertently extend shift durations beyond scheduled hours, which could trigger overtime alerts unexpectedly.
Consider adjusting the retry interval in the outbound campaign settings instead of modifying trunk headers. A slight delay before retrying can allow the carrier session to stabilize without impacting agent availability. This approach keeps the WFM data clean while maintaining call volume targets. Always test changes in a sandbox environment first to avoid disrupting live schedules.