Abstract: A method of facilitating the legal interception of IP connections, where two or more terminals can communicate with each other over the Internet using IPSec to provide security. The method comprises allocating to each terminal T1,T2 a public/private key pair for use in negotiating IKE and IPSec Security Associations (SAs) with other terminals. Where a terminal T1,T2 is coupled to the Internet via an access network 1,2, the private key of that terminal is stored within the access network at an interception server S1,S2. When an IP connection is initiated to or from a terminal T1,T2 on which a legal interception order has been placed, the private key stored for that terminal T1,T2 within the access network 1,2 is used to intercept the connection.

Abstract: A telecommunications system comprises a signalling network and a Voice over IP (VoIP) network. The signalling network in turn comprises gateway signalling points 6,7 for converting signalling messages between at least two different signalling protocols. The IP network comprises IP nodes 4 for routing IP datagrams, with at least certain of the IP nodes 4 being co-located with respective gateway signalling points 6,7, and with the co-located signalling points 6,7 being arranged in use to pass routing information to the respective IP nodes 4 to enable those nodes to prioritise and route incoming IP datagrams.

Abstract: A method of signalling in a telecommunications network to control a set of circuit switched channels between a network exchange and an Internet Access Server, alternatively known as Network Access Server (NAS). Signalling data is transmitted between the exchange and gateway node using SS7 Protocol, the exchange and gateway node being assigned respective SS7 Point Codes. The signalling data is then transmitted between the NAS and the gateway node using Internet Protocol (IP), the gateway node and the NAS being assigned respective IP addresses. The gateway node is provided with a look-up table mapping the NAS IP address to the exchange Point of Code and a set of identifiers corresponding to said set of channels. Signalling data received at the gateway node from the exchange is routed to the NAS using the IP address for the NAS obtained from the look-up table using the Point Code of the source exchange and a channel identifier conveyed with the signaling data.

Abstract: A method and apparatus enables a Network Access Server in association with a telecommunications switch to route incoming calls only to devices that have an actual connection to the Internet. A set of devices, RPG-Is, reformat incoming data from subscribers to a desired Internet Protocol. Initially, the expected network topology is recorded in memory for later comparison. During operation, each RPG-I attempts to detect the presence of every other expected RPG-I. If the presence of another RPG-I is not detected within a predetermined threshold period, then an alarm is issued. Error alarms are forwarded to application logic of the telecommunications switch so that the switch can avoid connecting a subscriber's call to an inoperable RPG-I. An alarm can also be forwarded to a network operator's terminal.