Technique for restoring a service in a network

An interrogation server arranged to process a service request relating to a user, the server comprising:

• a first transceiver module arranged to receive said service request relating to a user from a user equipment and to transfer it to a registration server;
• a second transceiver module arranged to interrogate a subscriber server in order to obtain in return an identifier of a nominal registration server associated with the user, or to receive capabilities that a registration server needs to possess in order to be capable of delivering the services authorized for a user;
• a selector module arranged to determine a replacement registration server on the basis of the received capabilities;
• and
• a control module arranged to cause a subscriber server to be interrogated so that, during a first stage, an identifier is obtained for the nominal registration server associated with the user, a transfer is made to the nominal registration server, and in the event of a failure to transfer the service request to said nominal registration server, capabilities are obtained;
• and also arranged, during a second stage, to act, when the nominal registration server is considered to be unreachable, so as to make a single transfer of the service request relating to a user to a registration server,
• wherein at least one of the first transceiver module, the second transceiver module, the selector module or the control module is implemented at least in part by a hardware component or a processor configured by a software component stored in a non-transitory computer-readable medium.

A subscriber server arranged to process a service request relating to a user, the server comprising:

• a transceiver module arranged to respond to an interrogation from an interrogation server, to supply the interrogation server with an identifier of a nominal registration server associated with the user or to supply the interrogation server with capabilities that a registration server needs to possess in order to be able to deliver the services authorized for a user;
• and
• a control module arranged to act during an optimization stage during which the nominal registration server is considered to be unreachable, to cause the capabilities to be supplied directly in response to a request for the identifier of said nominal registration server,
• wherein at least one of the transceiver module or the control module is implemented at least in part by a hardware component or a processor configured by a software component stored in a non-transitory computer-readable medium.

A system for processing a service request in a communications network, said system comprising:

• an interrogation server comprising:
• a first transceiver module arranged to receive said service request relating to a user from a user equipment and to transfer it to a registration server;
• a second transceiver module arranged to interrogate a subscriber server in order to obtain in return an identifier of a nominal registration server associated with the user, or to receive capabilities that a registration server needs to possess in order to be capable of delivering the services authorized for a user;
• a selector module arranged to determine a replacement registration server on the basis of the received capabilities;
• and
• a control module arranged to cause a subscriber server to be interrogated so that, during a first stage, an identifier is obtained for the nominal registration server associated with the user, a transfer is made to the nominal registration server, and in the event of a failure to transfer the service request to said nominal registration server, capabilities are obtained;
• and also arranged, during a second stage, to act, when the nominal registration server is considered to be unreachable, so as to make a single transfer of the service request relating to a user to a registration server;
• a calculation module arranged to update at least one counter relating to an unreachability status of the nominal registration server;
• and
• the subscriber server, comprising:
• a transceiver module arranged to respond to the interrogation from the interrogation server, in particular to supply the interrogation server with the identifier of the nominal registration server associated with the user or to supply the interrogation server with the capabilities that a registration server needs to possess in order to be capable of delivering the services authorized for a user;
• and
• a control module arranged to make the response to the interrogation server.

A non-transitory computer-readable medium having stored thereon a computer program including a series of program code instructions for allowing an interrogation server to execute steps of a method performed in a communications network to process a service request relating to a user, when said program is executed in a computer of the interrogation server, wherein the instructions configure the interrogation server to perform, during an optimization stage, acts of:

• a/ receiving said service request relating to a user and coming from a user equipment;
• b/ interrogating a subscriber server in order to obtain information enabling the service request to be processed;
• c/ receiving capabilities that a registration server needs to possess in order to be capable of delivering the services authorized for said user, the capabilities being received from a subscriber server;
• and
• d/ determining a replacement registration server on the basis of the received capabilities, and transferring the service request to the replacement registration server as determined;
• wherein, during a detection stage during which a nominal registration server associated with said user is considered to be reachable, said method comprises said acts a/ to d/, and further comprises the following acts prior to the act c/ of receiving capabilities:
• b1/ receiving an identifier of the nominal registration server in response to the interrogation of act b/;
• b2/ transferring the service request to the nominal registration server;
• and in the event of a failure of making this transfer to the nominal registration server:
• b3/ interrogating the subscriber server in order to obtain said capabilities;
• and once the nominal registration server is considered to be unreachable at the end of the detection stage, starting the optimization stage, during which the transfer of act d/ is the sole transfer of the service request that is made to a registration server.