Abstract: A method of operating a Call Session Control Function node within an IP Multimedia Subsystem network. The method comprises establishing a first session corresponding to a first IP Multimedia Subsystem communication service using a first Application Server, receiving a request for a further session corresponding to a further IP Multimedia Subsystem communication service, and forwarding said request to a further Application Server. Said further Application Server is additionally notified that said first communication service is ongoing and of the nature of said first session.

Abstract: A method of operating a Call Session Control Function node within an IP Multimedia Subsystem network. The method comprises establishing a first session corresponding to a first IP Multimedia Subsystem communication service using a first Application Server, receiving a request for a further session corresponding to a further IP Multimedia Subsystem communication service, and forwarding said request to a further Application Server. Said further Application Server is additionally notified that said first communication service is ongoing and of the nature of said first session.

Abstract: Apparatus, method and system for short message service center storage control, for allowing control of storage of a Mobile Originating Short Message, sent from an A-subscriber identified by a Mobile Subscriber ISDN number contained in a Mobile Application Part operation Mobile_Originating_Forward_Short_Message, in a Short Message Service Center belonging to a Public Land Mobile Network supporting Network Provider Number Portability. Use is made of a Number Portability Data Base including information specifying, for a plurality of Mobile subscribers identified by Mobile Subscriber ISDN numbers, whether the Mobile subscribers should-be Authorized or Not Authorized to store a Short Message in a Short Message Service Center belonging to the Public Land Mobile Network.