Abstract: Measures for transferring an established communication session in a telecommunications network, the communication session being established between one of a plurality of communication clients associated with a user and a remote device associated with a remote party. At a call control system located in the signaling path for the established communication session, a communication session transfer request is received from a device associated with the user, the communication session transfer request having been generated by and transmitted from the device. Transfer of the established communication session from the one communication client in the plurality of communication clients to another communication client in the plurality of communication clients is initiated at the call control system. The transfer is conducted on the basis of a preconfigured data set, specific to the user, identifying one or more of the plurality of communication clients associated with the user.

Abstract: Measures for use in operating a network node in a telecommunications network. At a network node located in a second part of the network, signaling messages transmitted between a server and end devices in an at least a first group are monitored. Each monitored signaling message includes a telephone dialing number for a given end device in the at least first group and an extension number for the given end device. On the basis of the monitoring, mapping data is stored which includes mappings between telephone dialing numbers and extension numbers for end devices in the at least first group. In response to detecting a loss of connectivity between a first part of the telecommunications network and the second part of the telecommunications network, extension number dialing request messages received from end devices in the first group are processed according to a detected loss of connectivity operating mode.

Abstract: Measures for use in operating a network node in a telecommunications network. At a network node located in a second part of the network, signaling messages transmitted between a server and end devices in an at least a first group are monitored. Each monitored signaling message includes a telephone dialing number for a given end device in the at least first group and an extension number for the given end device. On the basis of the monitoring, mapping data is stored which includes mappings between telephone dialing numbers and extension numbers for end devices in the at least first group. In response to detecting a loss of connectivity between a first part of the telecommunications network and the second part of the telecommunications network, extension number dialing request messages received from end devices in the first group are processed according to a detected loss of connectivity operating mode.

Abstract: Measures for transferring an established communication session in a telecommunications network, the communication session being established between one of a plurality of communication clients associated with a user and a remote device associated with a remote party. At a call control system located in the signaling path for the established communication session, a communication session transfer request is received from a device associated with the user, the communication session transfer request having been generated by and transmitted from the device. Transfer of the established communication session from the one communication client in the plurality of communication clients to another communication client in the plurality of communication clients is initiated at the call control system. The transfer is conducted on the basis of a preconfigured data set, specific to the user, identifying one or more of the plurality of communication clients associated with the user.

Abstract: Measures for transferring an established communication session in a telecommunications network, the communication session being established between one of a plurality of communication clients associated with a user and a remote device associated with a remote party. At a call control system located in the signaling path for the established communication session, a communication session transfer request is received from a device associated with the user, the communication session transfer request having been generated by and transmitted from the device. Transfer of the established communication session from the one communication client in the plurality of communication clients to another communication client in the plurality of communication clients is initiated at the call control system. The transfer is conducted on the basis of a preconfigured data set, specific to the user, identifying one or more of the plurality of communication clients associated with the user.

Abstract: Method, apparatus and computer program product for use in the upgrade of nodes in a group of nodes in a data communications network. One or more nodes in the group to which a given upgrade is yet to be applied are identified. A given node is selected from amongst the identified one or more nodes to which the given upgrade is yet to be applied as the leader node for the group. Data is transmitted indicating the selection of the given node as the leader node. The upgrade proceeds with the given node as the leader node.

Abstract: Maintaining a list of communication session servers which are currently in an active state and which are currently in a failed state, and which are currently responsible for providing communication services to which subscribers. Receiving a query in relation to a communication session involving a subscriber. In response to the list indicating that a communication session server which is currently responsible for providing communication services to the subscriber currently has an active state, responding to the query with an identifier for the communication session server. In response to the list indicating that the communication session server currently has a failed state, conducting a responsibility transfer operation to transfer responsibility for providing communication services to the subscriber from the communication session server to a different communication session server and responding to the query with an identifier for the different communication session server.

Abstract: Measures for transferring an established communication session in a telecommunications network, the communication session being established between one of a plurality of communication clients associated with a user and a remote device associated with a remote party. At a call control system located in the signaling path for the established communication session, a communication session transfer request is received from a device associated with the user, the communication session transfer request having been generated by and transmitted from the device. Transfer of the established communication session from the one communication client in the plurality of communication clients to another communication client in the plurality of communication clients is initiated at the call control system. The transfer is conducted on the basis of a preconfigured data set, specific to the user, identifying one or more of the plurality of communication clients associated with the user.

Abstract: Method, apparatus and computer program product for use in the upgrade of nodes in a group of nodes in a data communications network. One or more nodes in the group to which a given upgrade is yet to be applied are identified. A given node is selected from amongst the identified one or more nodes to which the given upgrade is yet to be applied as the leader node for the group. Data is transmitted indicating the selection of the given node as the leader node. The upgrade proceeds with the given node as the leader node.