Abstract: In a communication system a plurality of services can be provided for a user in a session. At least two of said services can be provided based on different service architectures. In the method a user is first provided with a session. A control entity is provided with information identifying the session and also with information identifying a service to be provided for the user during the session. Said identity information is processed at the control entity to verify if information associated with provision of services in the session is stored at the control entity. The provision of the service is controlled based on the results of the processing. In an embodiment services or groups of services are provided with unique identifiers. The service provisioning is then controlled based on said identifiers.