Abstract: A multi-stage (e.g., two-stage) packet-based lookup process using a Ternary Content Addressable Memory (TCAM) divided into partitions. The result of a first stage lookup is used to selectively search one of a plurality of TCAM partitions during the second stage. A subset of destination address bits may be used in the first stage to hash to a selected partition for the second stage. Alternatively, a partitioning algorithm segments a routing trie into partitions, and then, either a separate, small TCAM or one of the partitions is used in the first stage to map a prefix of the destination address to one of the TCAM partitions for use in the second stage. The “trie-based” algorithms may advantageously partition the trie such that each second stage partition comprises a substantially contiguous sequence of routing prefixes in a post-order traversal of the routing trie, together with one or more covering prefixes thereof.

Abstract: A method and apparatus for network routing in packet-based networks which advantageously takes traffic conditions into account dynamically in determining the “best route” for routing a packet to its intended destination. Illustratively, a potential function is employed whereby hypothetical electrostatic potential values are calculated at each node or link of a network, and the packets are routed in accordance with these potential function values (e.g., in the direction of the lowest neighboring value). The potential function values may be advantageously calculated based on queue lengths at the various nodes (or links) in combination with a minimum-cost distance calculated to the packet's intended destination.

Abstract: A method for exchanging routing information between I-BGP routers within an autonomous system (AS) advantageously enables a solution to both persistent route oscillation problems and transient route oscillation problems which may occur when using I-BGP in a given AS. Conventional I-BGP protocol techniques are extended by enabling I-BGP speakers (e.g., routers) to communicate a set of possible best paths to a given destination, rather than communicating only a single best path, to each of their I-BGP peers within the given AS. Specifically, a plurality of possible best paths to a destination are communicated (where there are in fact more than one) from an I-BGP speaker in a given AS to its I-BGP peers (within the given AS), for each neighboring AS that provides any such paths (i.e., routes to the destination).

Abstract: A method and apparatus for reducing the number of write operations during route updates in router forwarding engines eliminates “excess” (i.e., “redundant”) writes to the routing trie. One or more writes are “redundant” with respect to another write if the timestamp of the other write is the same as or later than (by an amount less than a given threshold) the timestamp of each of the one or more writes, and if the state of the routing trie after the other write has been applied is equivalent whether or not any of the one or more writes have also been applied. Excess writes may be advantageously eliminated when routes are either added to or withdrawn from the routing trie, and deleted subtrees may be advantageously cached for subsequent re-addition thereto.

Abstract: A method and apparatus for deforming the network topology of a multi-hop wireless network dynamically (i.e., in real time), in response to changing network traffic conditions and in order to advantageously reduce mean end-to-end network (transmission) delay. Two illustrative embodiments of the invention deform the network topology dynamically in response to traffic conditions (i) by changing the network connectivity between the existing network nodes and (ii) by adding one or more new nodes (and associated connections thereto and therefrom) to the network. In both cases, the traffic conditions may be fed into the algorithm in real time as, for example, a set of queue length measurements. Then, in response, the network is advantageously reorganized into a configuration that reduces the mean end-to-end network transmission delay.

Abstract: A reverse sandbox extends a private computing environment onto a standalone host in a public environment. The reverse sandbox includes a service director that receives service requests, classifies the service requests in accordance with security policies, selects a processing stack based on the classification and communicates the service request to the selected processing stack. A reverse sandbox embodiment may also include a compliance supervisor that constructs processing stacks with mediation modules based upon security policies. The mediation modules of the selected processing stack modify the service request and provide the modified service request to the resources of the standalone host.

Abstract: A multi-stage (e.g., two-stage) packet-based lookup process using a Ternary Content Addressable Memory (TCAM) divided into partitions. The result of a first stage lookup is used to selectively search one of a plurality of TCAM partitions during the second stage. A subset of destination address bits may be used in the first stage to hash to a selected partition for the second stage. Alternatively, a partitioning algorithm segments a routing trie into partitions, and then, either a separate, small TCAM or one of the partitions is used in the first stage to map a prefix of the destination address to one of the TCAM partitions for use in the second stage. The “trie-based” algorithms may advantageously partition the trie such that each second stage partition comprises a substantially contiguous sequence of routing prefixes in a post-order traversal of the routing trie, together with one or more covering prefixes thereof.

Abstract: A method and apparatus for network routing in packet-based networks which advantageously takes traffic conditions into account dynamically in determining the “best route” for routing a packet to its intended destination. Illustratively, a potential function is employed whereby hypothetical electrostatic potential values are calculated at each node or link of a network, and the packets are routed in accordance with these potential function values (e.g., in the direction of the lowest neighboring value). The potential function values may be advantageously calculated based on queue lengths at the various nodes (or links) in combination with a minimum-cost distance calculated to the packet's intended destination.

Abstract: A method and apparatus for reducing the number of write operations during route updates in router forwarding engines eliminates “excess” (i.e., “redundant”) writes to the routing trie. One or more writes are “redundant” with respect to another write if the timestamp of the other write is the same as or later than (by an amount less than a given threshold) the timestamp of each of the one or more writes, and if the state of the routing trie after the other write has been applied is equivalent whether or not any of the one or more writes have also been applied. Excess writes may be advantageously eliminated when routes are either added to or withdrawn from the routing trie, and deleted subtrees may be advantageously cached for subsequent re-addition thereto.

Abstract: A method and apparatus for generating a routing trie data structure for use in a pipelined forwarding engine such that potions of the trie may be advantageously allocated among the memories associated with the various pipeline stages. In accordance with one illustrative embodiment of the present invention, a dynamic programming technique is advantageously employed to build a trie which may be allocated to a plurality of pipeline stages such that the maximum memory allocated to a stage is minimized (thereby ensuring that the memory is relatively balanced across all pipeline stages). The trie which is built in accordance with this illustrative embodiment of the present invention is advantageously a fixed-stride trie containing exactly one trie level in the memory of each pipeline stage.

Abstract: A method for exchanging routing information between I-BGP routers within an autonomous system (AS) advantageously enables a solution to both persistent route oscillation problems and transient route oscillation problems which may occur when using I-BGP in a given AS. Conventional I-BGP protocol techniques are extended by enabling I-BGP speakers (e.g., routers) to communicate a set of possible best paths to a given destination, rather than communicating only a single best path, to each of their I-BGP peers within the given AS. Specifically, a plurality of possible best paths to a destination are communicated (where there are in fact more than one) from an I-BGP speaker in a given AS to its I-BGP peers (within the given AS), for each neighboring AS that provides any such paths (i.e., routes to the destination).