MessageListener implementations provided by Converged Application Server Java API SDK are solely meant for read-only purposes, such as logging. They must not be used for any type of SIP manipulation such as adding, removing, or modifying a session attribute or any other manipulation of a container-managed object.

The SIP container does not handle any sort of exception scenario; so it is not advisable for an application to rely on implementing the MessageListener interfaces for any type of SIP manipulation.