Abstract: Prefix searches for directing internet data packets are performed in a prefix search integrated circuit. The integrated circuit includes an array of search engines, each of which accesses a prefix search tree data structure to process a prefix search. An SDRAM is dedicated to each search engine, and SDRAMs share address and control pins to plural search engines on the IC chip. Internal nodes of the tree data structure are duplicated across banks of the SDRAMs to increase bandwidth, and leaf nodes are stored across the SDRAM banks to reduce storage requirements. Within each search engine, data stored in a data register from an SDRAM is compared to a prefix search key stored in a key register. Based on that comparison, an address is calculated to access further tree structure data from the SDRAM. Packet descriptors containing search keys are forwarded to the search engines from an input queue and the search results are forwarded to an output queue, the same packet order being maintained in the two queues.

Abstract: In a network router, a tree structure or a sorting network is used to compare scheduling values and select a packet to be forwarded from an appropriate queue. In the tree structure, each leaf represents the scheduling value of a queue and internal nodes of the structure represent winners in comparisons of scheduling values of sibling nodes of the tree structure. CBR scheduling values may first be compared to select a queue and, if transmission from a CBR queue is not timely, a packet may be selected using WFQ scheduling values. The scheduling values are updated to reflect variable packet lengths and byte stuffing in the prior packet. Scheduling may be performed in multiple stages.

Abstract: In a network router, a tree structure or a sorting network is used to compare scheduling values and select a packet to be forwarded from an appropriate queue. In the tree structure, each leaf represents the scheduling value of a queue and internal nodes of the structure represent winners in comparisons of scheduling values of sibling nodes of the tree structure. CBR scheduling values may first be compared to select a queue and, if transmission from a CBR queue is not timely, a packet may be selected using WFQ scheduling values. The scheduling values are updated to reflect variable packet lengths and byte stuffing in the prior packet. Scheduling may be performed in multiple stages.

Abstract: The required length of a route descriptor in a source routing system is obtained by inserting an implied exit field, use of run-length encoding, and use of variable-length encoding. In the variable-length encoding, codes having lesser bits are reserved for preferred directions. Preferred direction may be encoded in the routing header, and it may be implied by the arrival port.

Abstract: Prefix searches for directing internet data packets are performed in a prefix search integrated circuit. The integrated circuit includes an array of search engines, each of which accesses a prefix search tree data structure to process a prefix search. An SDRAM is dedicated to each search engine, and SDRAMs share address and control pins to plural search engines on the IC chip. Internal nodes of the tree data structure are duplicated across banks of the SDRAMs to increase bandwidth, and leaf nodes are stored across the SDRAM banks to reduce storage requirements. Within each search engine, data stored in a data register from an SDRAM is compared to a prefix search key stored in a key register. Based on that comparison, an address is calculated to access further tree structure data from the SDRAM. Packet descriptors containing search keys are forwarded to the search engines from an input queue and the search results are forwarded to an output queue, the same packet order being maintained in the two queues.

Abstract: Irregularities are provided in at least one dimension of a torus or mesh network for lower average path length and lower maximum channel load while increasing tolerance for omitted end-around connections. In preferred embodiments, all nodes supported on each backplane are connected in a single cycle which includes nodes on opposite sides of lower dimension tori. The cycles in adjacent backplanes hop different numbers of nodes.

Abstract: An internet router is implemented as a network fabric of fabric routers and links. The internet router receives data packets from trunk lines or other internet links and analyzes header information in the data packets to route the data packets to output internet links. The line interface also analyzes the header to define a fabric path through the router fabric. The internet packets are broken into flits which are transferred through the router according to a wormhole routing protocol. Flits are stored in fabric routers at storage locations assigned to virtual channels corresponding to destination internet links. The virtual channels and links within the fabric define virtual networks in which congestion in one virtual network is substantially nonblocking to data flow through other virtual networks. Arbitration is performed at each fabric router to assign packets to virtual channels and to assign virtual channels to output fabric links.

Abstract: An internet router is implemented as a network fabric of fabric routers and links. The internet router receives data packets from trunk lines or other internet links and analyzes header information in the data packets to route the data packets to output internet links. The line interface also analyzes the header to define a fabric path through the router fabric. The internet packets are broken into flits which are transferred through the router according to a wormhole routing protocol. Flits are stored in fabric routers at storage locations assigned to virtual channels corresponding to destination internet links. The virtual channels and links within the fabric define virtual networks in which congestion in one virtual network is substantially nonblocking to data flow through other virtual networks. Arbitration is performed at each fabric router to assign packets to virtual channels and to assign virtual channels to output fabric links.

Abstract: A list of prefix keys, including enclosing prefix key pairs, are stored in leaves of a tree structure. In the leaf nodes, a prefix search key is compared to a set of prefix keys to identify a longest matching prefix. Each leaf node includes a single result pointer to a block of results and a single enclosing pointer to a result in a block of results for another node. Internal nodes which point to subsequent nodes include partitioning nodes and table nodes. In each partitioning node, a prefix search key is compared to a set of prefix keys which point to subsequent nodes through a common pointer and an index. Within each node, a middle prefix key is stored ahead of sets of high and low prefixes.

Abstract: Prefix searches for directing internet data packets are performed in a prefix search integrated circuit. The integrated circuit includes an array of search engines, each of which accesses a prefix search tree data structure to process a prefix search. An SDRAM is dedicated to each search engine, and SDRAMs share address and control pins to plural search engines on the IC chip. Internal nodes of the tree data structure are duplicated across banks of the SDRALMs to increase bandwidth, and leaf nodes are stored across the SDRAM banks to reduce storage requirements. Within each search engine, data stored in a data register from an SDRAM is compared to a prefix search key stored in a key register. Based on that comparison, an address is calculated to access further tree structure data from the SDRAM. Packet descriptors containing search keys are forwarded to the search engines from an input queue and the search results are forwarded to an output queue, the same packet order being maintained in the two queues.

Abstract: An Internet router treats plural output ports with a common destination as a composite port. A routing table uses the IP address to determine a composite trunk to which the packet is to be forwarded. A forwarding table identifies a route along a routing fabric within the router to a specific output port of the composite port. Output ports and fabric routes are selected to maintain order within a flow by routing the flow along a single fabric route to a single output trunk. The forwarding table may favor output ports which are nearest to a packet input port, and the forwarding table may be modified to dynamically balance load across the trunks of a composite trunk.

Abstract: An internet router is implemented as a network fabric of fabric routers and links. The internet router receives data packets from trunk lines or other internet links and analyzes header information in the data packets to route the data packets to output internet links. The line interface also analyzes the header to define a fabric path through the router fabric. The internet packets are broken into flits which are transferred through the router according to a wormhole routing protocol. Flits are stored in fabric routers at storage locations assigned to virtual channels corresponding to destination internet links. The virtual channels and links within the fabric define virtual networks in which congestion in one virtual network is substantially nonblocking to data flow through other virtual networks. Arbitration is performed at each fabric router to assign packets to virtual channels and to assign virtual channels to output fabric links.

Abstract: An internet router is implemented as a network fabric of fabric routers and links. The internet router receives data packets from trunk lines or other internet links and analyzes header information in the data packets to route the data packets to output internet links. The line interface also analyzes the header to define a fabric path through the router fabric. The internet packets are broken into flits which are transferred through the router according to a wormhole routing protocol. Flits are stored in fabric routers at storage locations assigned to virtual channels corresponding to destination internet links. The virtual channels and links within the fabric define virtual networks in which congestion in one virtual network is substantially nonblocking to data flow through other virtual networks. Arbitration is performed at each fabric router to assign packets to virtual channels and to assign virtual channels to output fabric links.

Abstract: An Internet router treats plural output ports with a common destination as a composite port. A routing table uses the IP address to determine a composite trunk to which the packet is to be forwarded. A forwarding table identifies a route along a routing fabric within the router to a specific output port of the composite port. Output ports and fabric routes are selected to maintain order within a flow by routing the flow along a single fabric route to a single output trunk. The forwarding table may favor output ports which are nearest to a packet input port, and the forwarding table may be modified to dynamically balance load across the trunks of a composite trunk.

Abstract: A router routes data packets. The router includes input physical channels for incrementally receiving portions of the data packets, and output physical channels. The router further includes data buffers, coupled with the input and output physical channels, for storing the portions of the data packets. The router further includes control circuitry, coupled with the input and output physical channels and the data buffers, for generating virtual channel assignments that assign virtual channels to the data packets, and generating physical channel assignments that assign the output physical channels to the virtual channels. Each of the assignments is generated in response to queued arrival and credit events. The portions of the data packets are forwarded from the data buffers to the output physical channels according to the generate virtual and physical channel assignments.