Nortel Networks Corporation

Avaya Inc.

Avaya Holdings Limited

Janet Doong

Richard H Crump

Harish Sankaran

Arun Kudur

Xiangrong Cai

Mark F Leary

Shekhar Kshirsagar

Michael Kinzlmaier

Safe and efficient passing of information from a forwarding-plane to a control-plane is provided. The information can be passed from a forwarding-plane process to a control-plane process without having to modify the control-plane process and without requiring the processes to pass information via shared memory. The information is encoded in the forwarding-plane process. The encoded information is passed to the operating system, wherein the operating system interprets the encoded information and reports the information to the control plane process. The present invention can be advantageously utilized in passing multicast events from a forwarding-plane process to a control-plane process. Multicast events can be passed from a forwarding-plane process to a control-plane process without having to modify the control-plane process and without requiring the processes to pass messages via shared memory.

Passing information from a forwarding plane to a control plane

Described are a method and a device for efficiently switching multicast data flows from a shared distribution tree to a shortest path distribution tree. The method achieves an efficient and scalable tree switch that reduces the latency of multicast data transmitted from the source to receivers. A determination is made for each source group (S,G) entry in a portion of a forwarding plane database of a router as to whether a byte count for that entry exceeds a threshold value. A message sent from the forwarding plane to the router control plane indicates the (S,G) entries determined to have byte counts exceeding the respective threshold values. For each message entry, the respective shared distribution tree is switched to a shortest path distribution tree. The method achieves a substantial reduction in the number of inter-process messages exchanged between the control plane and the forwarding plane compared to conventional tree switchover techniques.

Method for multicast distribution tree switchover

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 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

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

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.

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 apparatus for translating a message between a first transmission protocol to a second transmission protocol limits buffer sizes for storing incoming and outcoming message data. To that end, each message has a message size that is no larger than a maximum message size, and the first protocol transports message data with message envelopes having an envelope size that is no larger than a maximum envelope size. The apparatus further includes a first protocol interface for interfacing with first protocol devices that communicate via the first protocol, a second protocol interface for interfacing with second protocol devices that communicate via the second protocol, and control logic that couples the first protocol interface with the second protocol interface.

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Chelmsford, MA, United States of America

Janet Doong