Abstract: Methods and apparatuses, including computer program products, are described for synchronization of shared initial filter criteria in an IP Multimedia Subsystem (IMS) network. A first computing device in the IMS network transmits a registration request to a second computing device in the IMS network. The first computing device receives a response to the registration request from the second computing device, including an identifier associated with a shared initial filter criteria set stored at the first computing device. The first computing device determines whether the shared initial filter criteria set corresponding to the identifier is stored at the first computing device and transmits a retrieval request to the second computing device if the shared initial filter criteria set corresponding to the identifier is not stored. The first computing device receives the shared initial filter criteria set from the second computing device, and stores the shared initial filter criteria set.

Abstract: A computer-implemented method for authorizing access by a user device to at least one service offered over an Internet Protocol (IP) network is provided. A server receives a message from the user device. The message indicates that the user device is configured to support the at least one service. The server then retrieves from a database policy data associated with the user device. The server validates based on the policy data that the user device is authorized to advertise the at least one service and the at least one service is available for access by the user device. If the at least one service is unauthorized or unavailable for access by the user device, the server modifies the message to indicate one or more authorized and available services for the user device without including the at least one service.

Abstract: A computer-implemented method for authorizing access by a user device to at least one service offered over an Internet Protocol (IP) network is provided. A server receives a message from the user device. The message indicates that the user device is configured to support the at least one service. The server then retrieves from a database policy data associated with the user device. The server validates based on the policy data that the user device is authorized to advertise the at least one service and the at least one service is available for access by the user device. If the at least one service is unauthorized or unavailable for access by the user device, the server modifies the message to indicate one or more authorized and available services for the user device without including the at least one service.

Abstract: Methods and apparatuses, including computer program products, are described for synchronization of shared initial filter criteria in an IP Multimedia Subsystem (IMS) network. A first computing device in the IMS network transmits a registration request to a second computing device in the IMS network. The first computing device receives a response to the registration request from the second computing device, including an identifier associated with a shared initial filter criteria set stored at the first computing device. The first computing device determines whether the shared initial filter criteria set corresponding to the identifier is stored at the first computing device and transmits a retrieval request to the second computing device if the shared initial filter criteria set corresponding to the identifier is not stored. The first computing device receives the shared initial filter criteria set from the second computing device, and stores the shared initial filter criteria set.

Abstract: A computer-implemented method for authorizing access by a user device to at least one service offered over an Internet Protocol (IP) network is provided. A server receives a message from the user device. The message indicates that the user device is configured to support the at least one service. The server then retrieves from a database policy data associated with the user device. The server validates based on the policy data that the user device is authorized to advertise the at least one service and the at least one service is available for access by the user device. If the at least one service is unauthorized or unavailable for access by the user device, the server modifies the message to indicate one or more authorized and available services for the user device without including the at least one service.

Abstract: Methods and apparatuses, including computer program products, are described for synchronization of shared initial filter criteria in an IP Multimedia Subsystem (IMS) network. A first computing device in the IMS network transmits a registration request to a second computing device in the IMS network. The first computing device receives a response to the registration request from the second computing device, including an identifier associated with a shared initial filter criteria set stored at the first computing device. The first computing device determines whether the shared initial filter criteria set corresponding to the identifier is stored at the first computing device and transmits a retrieval request to the second computing device if the shared initial filter criteria set corresponding to the identifier is not stored. The first computing device receives the shared initial filter criteria set from the second computing device, and stores the shared initial filter criteria set.

Abstract: Methods and apparatuses, including computer program products, are described for synchronization of shared initial filter criteria in an IP Multimedia Subsystem (IMS) network. A first computing device in the IMS network transmits a registration request to a second computing device in the IMS network. The first computing device receives a response to the registration request from the second computing device, including an identifier associated with a shared initial filter criteria set stored at the first computing device. The first computing device determines whether the shared initial filter criteria set corresponding to the identifier is stored at the first computing device and transmits a retrieval request to the second computing device if the shared initial filter criteria set corresponding to the identifier is not stored. The first computing device receives the shared initial filter criteria set from the second computing device, and stores the shared initial filter criteria set.

Abstract: A computer-implemented method for authorizing access by a user device to at least one service offered over an Internet Protocol (IP) network is provided. A server receives a message from the user device. The message indicates that the user device is configured to support the at least one service. The server then retrieves from a database policy data associated with the user device. The server validates based on the policy data that the user device is authorized to advertise the at least one service and the at least one service is available for access by the user device. If the at least one service is unauthorized or unavailable for access by the user device, the server modifies the message to indicate one or more authorized and available services for the user device without including the at least one service.

Abstract: A system and method for maintaining service availability for an Internet Protocol Multimedia Subsystem (IMS) network is provided. A primary network receives a request from one or more subscribers of the primary network to place a call. The primary network registers the one or more subscribers. The primary network assigns an identifier to data of the one or more registered subscribers for the registration. The identifier associates the one or more subscribers with the primary network upon migration of the one or more subscribers from the primary network to the secondary network. The secondary network monitors the primary network to detect an event on the primary network. The secondary network migrates the one or more subscribers from the secondary network to the primary network based on the identifier and after initiation of the migration in response to the occurrence of the event on the primary network.