Considerations for Implicit Service Route Use
When implicit service route support is enabled for a SIP interface (in IMS applications), the Oracle® Enterprise Session Border Controller stores the Service Route URIs from the Service-Route headers that are included in 200 OK responses to REGISTER messages. Subsequently, and even when a session agent is rendered invalid, re-REGISTER messages follow the route stored in the cache instead of using the one defined in the Oracle® Enterprise Session Border Controller.
However, you might not want to use this behavior when you send session agents offline. If you instead want use the route defined in the Oracle® Enterprise Session Border Controller, then you need to configure the SIP interface option called route-register-no-service-route.