Abstract: Apparatus for relaying packets between a first host and a second host and methods for sending packets between a first and second host are provided. The apparatus includes a memory for registering for the first host the following information: a relayed address of the first host, an address of the second host, and an outbound higher layer identifier and/or an inbound higher layer identifier. The apparatus further includes an outbound packet inspector for inspecting packets received from the first host and addressed to an address of the apparatus to determine whether they contain a registered outbound higher layer identifier and, if so, for forwarding the packets to the address of the second host and/or an inbound packet inspector for inspecting packets received from the second host and addressed to the relayed address to determine whether they contain a registered inbound higher layer identifier and, if so, for forwarding the packets to the address of the first host.

Abstract: A system and method for event notification and access control for Distributed Hash Tables (DHTs) using an event triggering mechanism for DHT-based Peer-to-Peer (P2P) overlay networks is described. According to an embodiment of the invention, a user interested in certain event can insert a trigger into the DHT. When the event occurs, the trigger fires and causes a pre-defined action to be executed. According to another embodiment of the invention, a user peer inserts a trigger resource record, which includes instructions to execute a specified action upon occurrence of the event, into the DHT. A monitored resource record, with which the event is or will be associated, is identified. A monitoring peer, responsible for maintaining the monitored resource record, is then identified. The trigger resource record is maintained at the monitoring peer.

Abstract: A method of managing a ring-based overlay network that is configured to allow routing of messages across an underlying IP network to destinations not specified by an IP address. The method comprises firstly sending a probe message from an initiating node of the overlay network around the ring, with each peer node forwarding the probe message to a successor or predecessor node. Upon detection of a forwarding failure at a node of the ring, a Probe error message is sent from that node to the initiating node. The initiating node represents the final destination for the Probe message.

Abstract: A node for use within an overlay network, such as a Distributed Hash Table based overlay network, and which is configured to route packets across the overlay network. The node comprises means for making a routing decision based upon a knowledge of the power consumption levels and/or power availability of a set of peer nodes in the overlay network.

Abstract: A method of maintaining routing tables at nodes of an overlay network, where a routing table of a given node contains, for each of a set of neighbouring successor and predecessor nodes, a mapping between an overlay network address of the node and a physical locator of the node. The method comprises, upon or immediately prior to departure of a node from the overlay network, sending a Leave request from the departing node (or one of the neighbouring nodes of the departing node aware of the departure) to each neighbouring node (or each other neighbouring node of the departing node), indicating the departure and containing one or more mappings for nodes not contained within the routing table of the recipient node. Each neighbouring node (or each other neighbouring node) receives the Leave request and uses said mapping(s) to update its routing table.

Abstract: An overlay network node (12, 20, 30 to 32) is arranged to provide robust reply routing for requests and replies travelling over the network. Each node comprises first means (35) which forwards each request originating in a source node (S) and destined for destination node (D). The node comprises second means (20, 36) which redirect replies if the node from which the corresponding requests were received is no long accessible. The reply is, for example, turned into a request containing the reply as its payload and is returned towards the source node according to the rules used for forwarding the requests.

Abstract: A method of enabling a user terminal to participate in floor control operations in a telecommunications conference operating a Binary Floor Control Protocol, BFCP. The method includes sending a first message from the user terminal to a gateway node. The first message includes information relating to floor control operations in the conference. The first message is inter-worked at the gateway node to generate a corresponding BFCP message. The BFCP message is forwarded to a Floor Control function.