Context:
Our EU-West BYOC environment is experiencing intermittent call drops during the initial interaction phase of our primary inbound IVR. The issue appears linked to SIP Session Timer expiration. The outbound provider sends a Session-Expires header of 180 seconds, while the Genesys Cloud ingress gateway defaults to a much shorter interval. Architect logs indicate the flow is still processing the initial language selection step when the SIP INVITE is terminated by the upstream carrier. The error observed in the conversation detail view is SIP 488 Not Acceptable Here, followed immediately by a BYE from the carrier side. This is not a network latency issue, as jitter and packet loss metrics remain within acceptable thresholds during the affected periods. The problem is most prevalent during high-volume windows where the ingress gateway might be under slight load, potentially delaying the SIP re-INVITE negotiation.
Question:
Could someone explain how to configure the Genesys Cloud SIP trunk settings to properly handle or extend the Session Timer negotiation? Specifically, is there a way to force the platform to accept the carrier’s Session-Expires value or to send a re-INVITE with a longer duration before the flow completes? We need to ensure the SIP session remains active for at least 300 seconds to accommodate complex flow logic without manual intervention on the carrier side.