Abstract: A wireless station having a wireless network device capable of providing a link-layer interface to a wireless network, a method operating at the link layer (L2) in the wireless station, and a carrier medium carrying computer readable code segments that when executed on a processor in the wireless station implement the method. The method includes, prior to the station being associated with a wireless network, wirelessly receiving L2 frames transmitted from one or more wireless access point of one or more wireless networks that the station can hear. The method further includes gathering information about the received L2 frames, including L2 information and L3 information. The L3 information includes whether an AP is sending an IP packet from a mobility agent, such that the station may associate with a wireless network that is in communication with the mobility agent. The method further includes storing information about the wireless networks that the station can hear in a database.

Abstract: A mobile router is configured for attaching to a selected router in a clustered network (e.g., a mobile ad hoc network) based on identifying a network topology model of the clustered network from received router advertisement messages that include tree information option fields specifying attributes of the network topology model. The mobile router selects which router advertisement originator to attach to based on correlating the attributes of the router advertisement originators relative to identified priorities, and orders the router advertisement originators within a default router list based on the identified priorities. If the mobile router detects a router from a second clustered network, the mobile router advertises to the attachment router that the second clustered network is reachable, enabling the two clustered networks to communicate using a point-to-point link between the respective attachment routers.

Abstract: Methods and apparatus for processing registration requests by a Home Agent supporting Mobile IP are disclosed. A registration request is received from each of a plurality of Mobile Nodes, the registration request specifying a care-of address. A binding is established between each of the plurality of Mobile Nodes and the associated care-of address, each of the plurality of Mobile Nodes being associated with one another. For instance, the plurality of Mobile Nodes may be statically or dynamically assigned the same Home Address. A tunnel is then created between the Home Agent and the care-of address for each of the plurality of Mobile Nodes, thereby enabling a server request to be distributed by the Home Agent to one of the plurality of Mobile Nodes via the associated tunnel. For instance, a server request addressed to the Home Address may be forwarded to one of the Mobile Nodes assigned that Home Address.

Abstract: Each mobile ad hoc node has an assigned hierarchy position within an identified tree-based aggregation group. Each ad hoc node is configured for selectively attaching to one of a plurality of available ad hoc nodes based on identifying a best match, for the assigned hierarchy position within the identified aggregation group, from among identifiable hierarchy positions of identifiable aggregation groups. Each ad hoc node also is configured for selectively attaching to any available ad hoc node based on a determined absence of any available ad hoc node advertising the identified aggregation group of the ad hoc node, or an aggregation group containing the identified aggregation group. Hence, a root node of an aggregation group can filter group-specific routing information from packets destined toward a network clusterhead, resulting in a scalable routing protocol that is not adversely affected by added nodes.

Abstract: Each mobile router in a mobile ad hoc network is configured for identifying routes to nearby nodes that are within a prescribed distance, based on storage of explicit paths specified within routing headers of packets transmitted from a host node to a destination node. Each mobile router also can selectively compress the routing header, based on the storage of the explicit path, resulting in a loose source route type routing header in the packet output from the mobile router. In addition, a routing header of a received packet can be expanded based on the mobile router inserting the explicit path, enabling mobile hosts in the explicit path to forward the packet according to strict source routing. The storage and compression of explicit paths also can be applied to packets specifying reverse routing headers, minimizing the size of the reverse routing headers.

Abstract: Each network node having at least one destination-oriented link toward a directed acyclic graph (DAG) destination can receive a corresponding set of path performance metrics via the destination-oriented link. The set of path performance metrics, initiated by the DAG destination outputting initial link metrics on each of its source-connecting links, identifies aggregate link metrics for a corresponding path to the DAG destination via the corresponding destination-oriented link. The network node outputs a corresponding updated set of path performance metrics on each of its source-connecting links based on the received set of path performance metrics and the corresponding link metric for the corresponding source-connecting link. Hence, each network node in the DAG can assess the performance of each connected path to the DAG destination, and forward a data packet via a selected destination-oriented link based on the corresponding path performance metrics and forwarding policies for the forwarded data packet.

Abstract: A mobile router is configured for optimized utilization of reverse routing headers, to specify a path between an originating mobile router and a home agent. Reverse routing headers enable each mobile router within the path to the home agent to specify its care of address, enabling the home agent to establish a bidirectional tunnel to the originating mobile router via the corresponding mobile router. The mobile router selectively updates the reverse routing header in a received packet by inserting the source address value of the received packet into the reverse routing header and inserting its corresponding care of address into the source address field, based on whether the mobile router lacks a routing table entry that specifies reachability of a most recent entry in the reverse routing header via the source address value. The mobile router also may request the originating mobile router to increase the reverse routing header size.

Abstract: Each network node in a network is configured for calculating a directed acylic graph that provides at least one path from all the other network nodes toward the one network node. The network node performs a modified shortest path first calculation by identifying next-hop nodes adjacent to the network node, and orienting the link of each next-hop node toward itself (i.e., the origin). The network node also identifies secondary adjacent nodes, adjacent to each of the next hop nodes, and extends paths from next-hop nodes to the associated secondary adjacent nodes while orienting each of the links of the path between adjacent nodes and next-hop nodes toward the next hop nodes. The paths of the nodes form a directed acyclic graph from any other network node toward the origin, enabling distribution of the directed acyclic graph to the other network nodes for optimized reachability to the network node.

Abstract: A mobile router is configured for attaching to a selected router in a mobile network based on identifying a network topology model of the mobile network from received router advertisement messages that include tree information option fields specifying attributes of the network topology model. The mobile router selects which router advertisement originator to attach to based on correlating the attributes of the router advertisement originators relative to identified priorities, and orders the router advertisement originators within a default router list based on the identified priorities.

Abstract: A mobile router is configured for attaching to a selected router in a clustered network (e.g., a mobile ad hoc network) based on identifying a network topology model of the clustered network from received router advertisement messages that include tree information option fields specifying attributes of the network topology model. The mobile router selects which router advertisement originator to attach to based on correlating the attributes of the router advertisement originators relative to identified priorities, and orders the router advertisement originators within a default router list based on the identified priorities. If the mobile router detects a router from a second clustered network, the mobile router advertises to the attachment router that the second clustered network is reachable, enabling the two clustered networks to communicate using a point-to-point link between the respective attachment routers.

Abstract: A default gateway router of a multi-homed site is configured for supplying, to a host device, a plurality of address prefixes having been advertised by respective exit routers providing respective connecting links for the multi-homed site to a wide area network. The default gateway router sends the address prefixes to the host device in a determined order based on a determined preference in the default gateway router for reaching the respective exit routers. The host device is configured for selecting a source address according to the determined order supplied by the default gateway router. The address also prefixes may be grouped according to identified destination prefixes, enabling the host device to select, for a given identified destination prefix, the source address according to the ordering of address prefixes within the corresponding group.

Abstract: Each router in a network is configured for executing a link state routing protocol based on outputting a corresponding first link state advertisement message describing a connected link of the router and that specifies a first dynamic routing metric identifying a first cost of the connected link, and a corresponding variation metric identifying a statistical variation of the dynamic routing metric. Each router also is configured for selectively outputting a corresponding second link state advertisement message describing the connected link and that specifies the corresponding variation metric and an updated dynamic routing metric identifying an updated cost of the connected link relative to the first cost, the second link state advertisement message selectively output based on the updated dynamic routing metric differing from the first dynamic routing metric by more than the variation metric, or the router having received another link state advertisement from another router in the network.

Abstract: Each mobile router in an ad hoc mobile network is configured for concurrently attaching to multiple parents advertising respective parent depths relative to a clusterhead of the ad hoc mobile network. The mobile router selects an advertised depth relative to the clusterhead based on adding a prescribed increment to a maximum one of the parent depths, enabling the mobile routers to form a directed acyclic graph relative to the clusterhead. Each mobile router sends to each of its parents a neighbor advertisement message specifying at least one reachable prefix, a corresponding cost for reaching the reachable prefix, and a corresponding sequence identifier that enables the parents to validate the neighbor advertisement message relative to stored router entries. Hence, mobile routers automatically can form a directed acylic graph relative to the clusterhead, and can distribute routing information with minimal overhead.

Abstract: An IPv6 mobile node establishes an IPv4 connection with an IPv6 router having an IPv4 interface and configured as a Mobility Anchor Point (MAP) according to Hierarchical Mobile IPv6 Protocol. The MAP assigns a valid IPv6 care-of address to the IPv6 mobile node in response to receiving an IPv4 packet carrying an IPv6 packet requesting a valid care-of address. The IPv4 packet includes IPv4 source and destination addresses, a TCP/UDP source port and TCP/UDP destination port, and a synthetic tag address in the IPv6 source address field. The synthetic tag address includes a unique identifier that enables the MAP to associate the valid IPv6 care-of address with the IPv6 mobile node. Hence, the MAP forwards an IPv6 packet, carried via the IPv4 connection from the source IPv6 mobile node, onto an IPv6 network with an IPv6 source address field that specifies the assigned valid IPv6 care-of address.

Abstract: Gateways providing connectivity for respective private IPv4 networks to an IPv6 network establish communications between IPv4 nodes in the private network. Network address translation-protocol translation (NAT-PT) state entries are created by gateway pairs enabling translation of IPv4 packets between first and second IPv4 nodes in respective first and second IPv4 private networks into IPv6 packets for transmission via the IPv6 network. Each NAT-PT state entry specifies the IPv6 addresses for the first and second IPv4 nodes, and the IPv4 addresses used to identify the first and second IPv4 nodes in the corresponding private IPv4 network. Each gateway is configured for generating the IPv6 address for each local IPv4 node based on prepending its corresponding assigned private IPv4 address with a corresponding prescribed IPv6 prefix assigned to the gateway.

Abstract: An IPv4 host is able to maintain connectivity within an access network while moving among access points of the access network, based on receiving a unique assigned IPv4 address from a clusterhead of the access network. Any DHCP request by the IPv4 host is sent via the connecting access point to the clusterhead. The clusterhead, providing connectivity for hosts in the access network to a wide area network based on respective entries, assigns the IPv4 address to the IPv4 host, based on storing an entry including the IPv4 address and an IP-based identifier of the connecting access point, and sends a DHCP response to the IPv4 host via the connecting access point. A second DHCP request from the IPv4 host to a second access point causes the clusterhead to update the entry with the second access point identifier, enabling the IPv4 host to continue use of the assigned IPv4 address.

Abstract: Mobile routers in a tree-based network topology with a single clusterhead in an ad hoc network establish connectivity based on each attached mobile router sending a neighbor advertisement message to an attachment mobile router via a corresponding egress interface. Any neighbor advertisement message received by a mobile router is used to identify specified network prefixes that are reachable via the source of the neighbor advertisement message. Each attached mobile router outputs to its attachment router another neighbor advertisement message that specifies the network prefix used by the mobile router, and the specified network prefixes from its attached mobile routers. The mobile router also identifies peer mobile routers having the same depth, and selectively shares limited routing information with the peer routers, enabling the mobile router to bypass the clusterhead and reach remote prefixes via the peer routers without burdening the tree.

Abstract: A source IPv6 mobile router is configured for establishing an IPv4 tunnel with destination IPv6 mobile router using a synthetic tag address, specifying a forwarding protocol, and IPv4 source and destination addresses. If an optional transport header is used (e.g, UDP port), the source port and destination port also are added to the synthetic tag address. The IPv6 packet includes a reverse routing header that enables the destination IPv6 mobile router to recover routing information for reaching the source IPv6 mobile router via the IPv4 network. Hence, all IPv4 routing information that may be needed by the destination IPv6 mobile router in sending an IPv6 reply packet back to the source IPv6 mobile router is maintained in the routing header specified in the IPv6 reply packet.

Abstract: The invention enables the surveillance of computer-like devices while they are connected to a communications network. This latter includes a Network Surveillance Server (NSS). Upon joining said communications network, a device is first required to log-in to NSS. After which, NSS polls it while connected on the network so that an alarm can be issued, from NSS, to a central surveillance unit, if the device fails responding to polling. Hence, prior to leaving the communications network, the computer-like device is also required to log-out to NSS. Thus, as long as it is connected to the communications network, the computer-like device is watched.

Abstract: A network includes network nodes and a gateway. Each network node has a corresponding unique in-site IPv6 address for communication within a prescribed site, each in-site IPv6 address having a first IPv6 address prefix that is not advertised outside of the prescribed site. Network nodes can obtain from within the prescribed site a unique extra-site IPv6 address for mobile or extra-site communications. The extra-site IPv6 address has a second IPv6 address prefix, distinct from the first IPv6 address prefix, advertised by the gateway to the prescribed site and the wide area network. The gateway establishes a secure connection (e.g., tunnel) with each corresponding IPv6 node using its corresponding extra-site IPv6 address, and creates a corresponding binding cache entry specifying the corresponding extra-site IPv6 address and in-site IPv6 address. Hence, the gateway provides wide area network access while maintaining secrecy of the in-site IPv6 addresses.