Extreme Networks, Inc.

Bay Networks, Inc.

Andrew H Smith

Michael Yip

Stephen R Haddock

Justin N Chueh

Shehzad T Merchant

Asher Waldfogel

Ross W Callon

David K Parker

Steven R Willis

William M Salkewicz

Erik Rustan Swenson

A flexible, policy-based, mechanism for managing, monitoring, and prioritizing traffic within a network and allocating bandwidth to achieve true quality of service (QoS) is provided. According to one aspect of the present invention, a method is provided for managing bandwidth allocation in a network that employs a non-deterministic access protocol, such as an Ethernet network. A packet forwarding device receives information indicative of a set of traffic groups, such as: a MAC address, or IEEE 802.1p priority indicator or 802.1Q frame tag, if the QoS policy is based upon individual station applications; or a physical port if the QoS policy is based purely upon topology. The packet forwarding device additionally receives bandwidth parameters corresponding to the traffic groups. After receiving a packet associated with one of the traffic groups on a first port, the packet forwarding device schedules the packet for transmission from a second port based upon bandwidth parameters corresponding to the traffic group with which the packet is associated. According to another aspect of the present invention, a method is provided for managing bandwidth allocation in a packet forwarding device. The packet forwarding device receives information indicative of a set of traffic groups. The packet forwarding device additionally receives information defining a QoS policy for the traffic groups. After a packet is received by the packet forwarding device, a traffic group with which the packet is associated is identified. Subsequently, rather than relying on an end-to-end signaling protocol for scheduling, the packet is scheduled for transmission based upon the QoS policy for the identified traffic group.

Policy based quality of service

A packet switching device having a central shared memory and a number of medium access controllers each coupled to a communications medium to exchange data packets therewith, and a controller coupled to each medium access controller via a data path to exchange data packets with the media access controller. The controller has a number of data path controllers each connected to each medium access controller via a separate and like portion of the data path to exchange a corresponding portion of the data packets with the medium access controller. The data path controllers each have a number of buffers each connected to one of the medium access controllers to which the data path controller is connected, to hold the portion of the data packets exchanged with the corresponding medium access controller. Each data path controller has a selector that selects the buffer from which to transmit or receive the portion of the data packets with the central shared memory and control logic that controls the selector to concurrently select the buffer corresponding to the same medium access controller. A comparison engine associated with each data path controller detects the slice of a field in a data packet buffered in the corresponding data path controller and computes a hashing function on the contents of the slice of the field to generate a hash key. A packet forwarding controller reads one or more entries from a hash bucket in a forwarding database indexed by the hash key and sends the entries to the comparison logic. The comparison logic compares the slice of the field in the buffer to each of the entries and returns the results of the compare to a packet forwarding controller. The forwarding controller then forwards, filters or identifies packets based on the results of the comparisons done on each slice of a field in the packets.

Sliced comparison engine architecture and method for a LAN switch

A network router that routes internetwork packets between distinct networks coupled to the same physical interface. The router comprises a port for coupling to a multiplexing fabric that carries internetwork traffic for a plurality of distinct networks and a routing engine that routes internetwork traffic between the plurality of networks using the port. According to various embodiments, the multiplexing fabric may be a switched fabric or a shared media fabric. The multiplexing fabric may also be used to connect networks that operate according to different protocols to the same port.

Network router that routes internetwork packets between distinct

A system for managing virtual circuits and determining proper routing of packets in a network environment. The network includes a connection-oriented subnetwork and an arrangement of routers coupled to the connection-oriented subnetwork. The system determines paths to each exit router by considering all possible paths through the connection-oriented subnetwork. The system also determines paths to each exit router by considering existing virutal circuits through the connection-oriented subnetwork. Finally, the system determines and establishes a most beneficial new virtual circuit for the network. Additionally, the rate at which new virtual circuits are established may be regulated by the system.

Method and apparatus for managing virtual circuits and routing packets

Growing community of inventors

Palo Alto, CA, United States of America

Andrew H Smith