Abstract: A communications system comprising a target node and at least one source node arranged for communication of messages there between; in which the target node comprises means for processing at least some of the messages received from the at least one source node and means for detecting the processing load of the target node; in which the target node comprises means for notifying the at least one source node when a specific processing load level has been reached or exceeded; and in which each source node comprises means for reducing, responsive to the notification, the rate at which messages are sent to the target node.

Abstract: The invention relates to a data communications network and a method of operation thereof. A data communications network (14) is described which includes a call server (58, 60, 62, 64) for the purpose of signalling, and a routing server (66, 68) for the purpose of routing to permit communication between users of the network. The call server (58, 60, 62, 64) is operable to send a request to the routing server (66, 68) for the purpose of obtaining the identity of another call server (58, 60, 62, 64) to which it is required to communicate. The request is provided with a parameter which relates to the origin of the communication within the data network (14) to enable a desired routing of the communication through the network.

Abstract: A communications system comprising a target node and at least one source node arranged for communication of messages there between; in which the target node comprises means for processing at least some of the messages received from the at least one source node and means for detecting the processing load of the target node; in which the target node comprises means for notifying the at least one source node when a specific processing load level has been reached or exceeded; and in which each source node comprises means for reducing, responsive to the notification, the rate at which messages are sent to the target node.

Abstract: The invention relates to a data communications network and a method of operation thereof. A data communications network (14) is described which includes a call server (58, 60, 62, 64) for the purpose of signalling, and a routing server (66, 68) for the purpose of routing to permit communication between users of the network. The call server (58, 60, 62, 64) is operable to send a request to the routing server (66, 68) for the purpose of obtaining the identity of another call server (58, 60, 62, 64) to which it is required to communicate. The request is provided with a parameter which relates to the origin of the communication within the data network (14) to enable a desired routing of the communication through the network.

Abstract: A packet control means for checking packets according to a plurality of rules, in which each packet is associated with a control value; the packet control means comprising index means for generating an index value from the control value associated with a packet and means for using the index value to access a rule for checking the packet from the plurality of rules. The control value is set by the packet control means. Advantageously, the packet checking always requires a single access to the plurality of rules, allowing for faster operation.