Nortel Networks Corporation

Richard H Crump

Janet Doong

Mark F Leary

Shuching Shieh

Ellis L Wong

Donald F Betsinger

Shekhar Kshirsagar

Xiangrong Cai

Manish Patel

Timothy Cunningham

Todd Short

Okoziem Allen

Donald McGinley

Sandipan Basu

Michael Kinzlmaier

Frank Barnes

Arvind Kukreja

Joseph Flaherty

Yue Long Chen

A domain manager of a router uses a mapping array that includes pointers to associate interfaces of the router with routing tables. The domain manager executes a single IP stack to receive packets from a plurality of address domains through the interfaces, and identify routing tables according to the mapping array. The mapping array associates interfaces connecting to the same address domain with the same routing table. Information in each of the routing tables is updated independently of other routing tables.

Central control of multiple address domains within a router

A single address configuration table entry maps multiple source devices in a source network to a single destination device in a destination network. The single address configuration table entry is used when any of the source devices initiates a connection to the destination device. The single address configuration table entry includes a 'wildcard' for matching the source address of connection requests that are originated by any of the multiple source devices and destined for the destination device. When a connection is initiated by a source device, certain address/channel information is dynamically allocated in order to map the source device to the destination device. A dynamic routing table entry is installed in a dynamic routing table in order to map the source device to the destination device using the dynamically allocated address/channel information.

Correlating data streams of different protocols

Described are a system and method of providing simultaneous lock-free access by a write process and at least one read process to records. The records are organized according to a first search data structure and according to a second search data structure. When searching for a particular record, the search occurs along a search path determined by the first search data structure until a record is accessed that indicates that the first search data structure is in an intermediate state. The searching for the particular record then continues along a search path determined by the second search data structure in response to the record that indicates that the first search data structure is in an intermediate state.

Concurrent lock-free access to a record by write and read processes

Described are a system and computer-implemented method for searching and updating a routing table for forwarding IP packets through a communications network. Records containing IP address prefixes are organized in a binary tree data structure. When inserting a new record, one of the records in the binary tree data structure is identified as an enclosing record having an associated record data range that encloses record data of the new record. An enclosing pointer of the new record is set to point to the identified enclosing record. When searching for a longest matching prefix for a destination IP address, the binary tree data structure is traversed and one of the records in the binary tree data structure is identified as an enclosing record, which is returned as the longest matching prefix.

Routing table for forwarding Internet Protocol (IP) packets through a communications network

One or more addresses are encoded into a single regular expression. The regular expression may be used for configuring and/or storing addressing information in a network device.

Encoding addresses in a communication system

A multicast network device, such as a router, may support a plurality of multicast routing protocols. Each multicast routing protocol maintains its own routing table that stores the multicast routes known to the multicast routing protocol. A unicast routing table may also be included in the network device. Some multicast protocols make us of unicast as well as multicast routes. A single multicast routing table is provided to store the multicast routes for each multicast routing protocol and a selected set of unicast routes form the unicast routing table. Multicast routing table management logic controls the content of the multicast routing table. The single multicast routing table allows for efficient access to the multicast and unicast routes as well as for the exchange of routing information between different multicast routing protocols.

Method, apparatus and system for management of multicast routes for a plurality of routing protocols in a network device

A multicast network device, such as a route may support a plurality of multicast routing protocols. A single multicast routing table may be provided to store the multicast routes for each multicast routing protocol and a selected set of unicast routes from a unicast routing table. In order to synchronize route changes in the multicast routing table with the plurality of multicast routing protocols, a route ID value is assigned to each route in the multicast routing table. Each multicast routing protocol is assigned a bookmark in a route change queue, where the bookmark is assigned the route ID value of the last route processed by the multicast routing protocol. When a route is changed, the route is assigned a new route ID value and stored in the route change queue. A multicast routing protocol may determine if a route change has occurred by comparing its bookmark to the highest route ID value in the route change queue.

Method for synchronization of multicast routing table changes with a plurality of multicast routing protocols

An information routing system and apparatus includes separate control and forwarding planes. The control plane is split into box management control functions and routing control functions. The box management control functions are isolated to a single processing card, while the routing control functions are distributed across multiple processing cards. The routing table is also distributed across multiple processing cards. The multiple processing cards are interconnected via a high-speed backplane bus for control plane traffic and by a fabric for forwarding plane traffic.

Information routing system and apparatus

A management information base (MIB) for a multi-domain network address translator provides management objects for configuring and controlling the multi-domain network address translator. The MIB includes management objects for defining a domain-specific source address filter range, which is a range of addresses used to detect domain-specific packets that require domain-specific network address translation forwarding. The domain-specific source address filter management objects include a beginning address, a prefix length, a domain indicator, and a domain-specific translation pool indicator. The MIB also includes management objects for defining a domain-specific translation pool, which is a range of addresses from which domain-specific translation addresses are selected for domain-specific network address translation forwarding. The domain-specific translation pool management objects include a beginning address, a prefix length, and a domain indicator.

Management information base for a multi-domain network address translator

Each connection-oriented client in a network device is bound to its own communication channel. The communication channel may be an X.25 logical channel having a single virtual circuit.

Apparatus and method for binding a connection-oriented client to a communication channel

A single address configuration table entry maps multiple source devices in a source network to a single destination device in a destination network. The single address configuration table entry is used when any of the source devices initiates a connection to the destination device. The single address configuration table entry includes a &ldquo;wildcard&rdquo; for matching the source address of connection requests that are originated by any of the multiple source devices and destined for the destination device. When a connection is initiated by a source device, certain address/channel information is dynamically allocated in order to map the source device to the destination device. A dynamic routing table entry is installed in a dynamic routing table in order to map the source device to the destination device using the dynamically allocated address/channel information.

A system, device, and method for interfacing multiple protocol stacks in a communication network utilizes a virtual circuit subsystem to interconnect protocol stacks internally within a network device. The virtual circuit subsystem establishes a virtual connection between at least a first protocol of a first protocol stack and a second protocol of a second protocol stack. The virtual circuit subsystem enables messages to be exchanged between the first protocol of the first protocol stack and the second protocol of the second protocol stack over the virtual connection. Specifically, the virtual circuit subsystem converts a transmitted message received from the first protocol into a received message for the second protocol, and converts a transmitted message received from the second protocol into a received message for the first protocol.

Apparatus and method for interfacing multiple protocol stacks in a communication network

A method, translating apparatus, apparatus comprising a computer readable medium, and system for error recovery in a mixed protocol communication network includes a translation function that communicates with a first device using a first communication protocol and a second device using a second communication protocol. When the translation function determines that a connection failure occurred between the translation function and the second device, the translation function completes a first link reset procedure with the first device to suspend data flow between the first device and the translation function, completes a connection establishment procedure with the second device to establish a connection between the translation function and the second device, and then completes a second link reset procedure with the first device to enable data flow between the first device and the translation function.

Error recovery in a mixed protocol networks

An apparatus and method of requesting retransmission of at least a portion of a message (having a plurality of message segments) from a sender utilizes message units in a memory device for storing data relating to retransmit messages. In particular, each message unit in the memory has data for one message segment. To that end, a retransmit message requesting retransmission of a set of message segments to a given receiver is received from the given receiver. The given retransmit message then is parsed to determine both the identity of the given receiver, and the identity of the set of message segments requested by the given receiver. A message unit then is produced in the memory for each of the set of message segments that does not have an existing message unit in memory. Data representing the identity of the given receiver then is added to all message units for the set of message segments.

Apparatus and method of requesting retransmission of a message across a network

An efficient technique for recovering multiple connections detects a connection failure affecting multiple clients, selects one of the number of affected clients, repeatedly attempts to reestablish the failed connection between the selected client and the server until the connection is successfully re-established, and then re-establishes the connections for the remaining clients.

Growing community of inventors

Boston, MA, United States of America

Richard H Crump