Systems for graceful termination of support for session initiation protocol communications on a server are described. Systems include techniques for setting a time period for gracefully terminating such support, for sending a service unavailable message to a client, for causing the server to maintain support, until no later than the expiration of the time period for terminating support, for uncompleted session initiation protocol invites accepted by the server before sending the service unavailable message to the client, and for terminating support for session initiation protocol communications on the server no later than upon expiration of the time period for terminating support. Methods for graceful termination of such support and computer-readable storage media whose contents cause a computer system to perform a graceful termination of such support are also described.