Sinch Scheduled Maintenance - Elastic SIP Trunking - final 603+ deployment

Scheduled for Jul 9, 12:00 - 14:00 UTC

Scheduled

Sinch Elastic SIP Trunking will be undergoing maintenance to complete the release for "603+". We will also be deploying minor bug fixes for services supporting CNAM lookups, RPID and PAI header support, and 911/933 emergency callback support.

"603+" is a newer SIP response code used in U.S. voice networks to signal that a call was blocked by the network, usually because it was identified as likely illegal, fraudulent, or unwanted traffic. Due to unforeseen circumstances, the full release for "603+" has been postponed several times - we sincerely apologize for the confusion. We anticipate July 9, 2026 to be the final release to support "603+".

The scheduled work is not expected to impact services. This is being sent as a courtesy notice in the event that you experience issues with your service during the maintenance window.

Please contact support@sinch.com for further information.

Posted Jul 03, 2026 - 16:34 UTC

This scheduled maintenance affects: Elastic SIP Trunking (API, Inbound Calling, Outbound Calling, International Calling, 9-1-1 / Emergency Services).