Abstract: A mobile node stores information identifying a number of possible mobility registration servers so that it can select a server based on its geographical location rather than simply using its default server. Selection will depend on the type of ID data stored. If partially completed FQDNs are stored, a country code is added to see if this corresponds to a local server. Alternatively IP addresses can be stored and chosen by prefix matching with a Care-of-Address.

Abstract: A method of managing switching of a virtual private network (VPN) tunnel termination point from a first address to a second address. The VPN operates between a fixed network node and a mobile node which defines the termination point. The address of the mobile mode is switched from the first address to the second address and a notification from the mobile node to the fixed node is sent to indicate that the address of the mobile has changed from the first address to the second address. Verification of the trustworthiness of the second address is also then made. A searching manager for performing the method is also disclosed.

Abstract: A method of managing switching of a virtual private network (VPN) tunnel termination point from a first address to a second address. The VPN operates between a fixed network node and a mobile node which defines the termination point. The address of the mobile mode is switched from the first address to the second address and a notification from the mobile node to the fixed node is sent to indicate that the address of the mobile has changed from the first address to the second address. Verification of the trustworthiness of the second address is also then made. A searching manager for performing the method is also disclosed.

Abstract: Duplicate Address Detection Optimisation is achieved by allocating a temporary address to a mobile node by an access muter that it uses to receive time critical data whilst the conventional DAD process completes on An address generated by the mobile node itself.

Abstract: Cryptographic Optimisation for Duplicate Address Detection Cryptographic Optimisation for Duplicate Address Detection is achieved by providing access routers with the cryptographic key and auxiliary parameters such that the access routers can generate CGA addresses on behalf of the MN and return these CGA addresses to the MN.

Abstract: When mobile communication is handed over from a first link to a second like, in order to relinquish resources as soon as possible, the release of resources allocated to the first link is initiated in response to the generation of the ACK signal by the mobile node, rather than waiting for a refresh command to time out.

Abstract: A dual mode (e.g. WLAN/UMTS) terminal with two network interfaces sends one interface to sleep mode following handover from one network to the other. Here sleep mode is synchronised with the end of the data stream, either by marking the stream or in response to sending a handover related SIP ACK message to the corresponding node.