Extreme Networks, Inc.

Other

Herb Schneider

Stephen R Haddock

Erik R Swenson

Justin N Chueh

R Steven Smith

Daniel J Cimino

Matthew T Knudstrup

Steve Haddock

Siddharth Khattar

Aaron C Tyler

Michael Yip

David K Parker

David S Gere

James C Yang

Nitin Bhandari

Nick G Suizo

Brian J Ray

David Scott Parker

Curt Berg

Mark Thomas Lytwyn

Brian Kline

James Yang

Brian Ray

David Gere

A method and system for integrating network policy enforcement into an existing network infrastructure comprises a communications bus that links expert policy devices, such as intrusion prevention devices, with one or more connection points. The connection points are network devices that are equipped with enforcement logic for receiving reports of events via a published interface on the communications bus about the existing network infrastructure from either the policy devices or the connection points themselves, and enforcing policy at the connection points by generating an action in response to the reported events, including actions to block traffic, remediate devices, limit bandwidth, and the like, until the reported event has been addressed in a manner that ensures the security of the existing network infrastructure.

Integrated network policy enforcement

A wireless network access point with an integrated sensor to sense and receive input unrelated to control of or data transmitted via the wireless network access point.

Wireless network access point and sensor

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, 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 to exchange a corresponding portion of the data packets with the medium access controller. The data path controllers each have a number of buffers 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 exchange 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.

Data path architecture for a LAN switch

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.

A network interconnect device and message exchange protocol for forwarding data among packet forwarding devices are provided. According to one aspect of the present invention, data is forwarded between a first and second packet forwarding device coupled to an interconnect device. The interconnect device receives a menu message from the first packet forwarding device that indicates one or more types of data that are awaiting transmission on the first packet forwarding device. Based upon the menu message, the interconnect device transmits an order message selecting a type of data of the one or more types of data awaiting transmission to the first packet forwarding device. The interconnect device receives a message from the first packet forwarding device containing data of the type selected by the order message. The interconnect device then forwards the data to the second packet forwarding device. According to another aspect of the present invention, data is forwarded among multiple packet forwarding devices through an interconnect device by selecting a configuration of the interconnect device based upon ports to which the packet forwarding devices have data to transfer. For each of the ports of the interconnect device, an indication of ports to which an attached packet forwarding device has data to transfer is received. Based upon these port indications, a configuration of the interconnect device is selected that contains non-conflicting paths through the interconnect device. Data is then forwarded in accordance with the selected configuration by forwarding data from those of the of packet forwarding devices coupled to ports that have been selected as source ports to corresponding destination ports.

Network interconnect device and protocol for communicating data among

A repeater that prevents a node involved in a collision from detecting that the collision occurred, and transmits the data packet received from that node to all other nodes connected to the repeater. The repeater accomplishes this by repeating the data packet received from that node during the collision, and discarding the data packets received from other nodes, thereby allowing a valid data packet to traverse the repeater and all communication medium segments attached thereto. The repeater maintains a count of the collisions and retransmission attempts experienced by each node since that node's last successful data packet transmission. The count is used to prioritize which of the nodes involved in a subsequent collision will be allowed to continue to transmit. Such prioritization reduces any disparity in the number of retransmission attempts experienced by each node, thereby reducing the likelihood of a node dropping a data packet as occurs when the maximum number of retransmission attempts allowed for such node is reached.

Method and apparatus for arbitrating data transmission in a CSMA/CD LAN

An improved repeater or hub in a CSMA/CD based LAN that provides deterministic access to a shared communication medium for a limited number of nodes and improves the nondeterministic access latency for up to the maximum number of nodes allowed to be coupled to the repeater without requiring any modification to the adapter in each of the nodes. The repeater prevents a node involved in a collision from detecting that the collision occurred, and transmits the data packet received from that node to all other nodes connected to the repeater. The repeater accomplishes this by repeating the data packet received from that node during the collision, and discarding the data packets received from other nodes, thereby improving the performance of a CSMA/CD LAN by allowing a valid data packet to traverse the repeater and all communication medium segments attached thereto. When selecting which node shall continue transmitting, the repeater gives priority to the node with the currently highest number of outstanding packet retransmission attempts.

Repeater providing for deterministic access in a LAN utilizing the

A message exchange protocol for interconnecting packet forwarding devices through an intermediate network interconnect device is provided. According to one aspect of the present invention, a method is provided for communicating data between packet forwarding devices. The presence of an interconnect device that is coupled between a first packet forwarding device and a second packet forwarding device is detected by recognizing a configuration sequence, for example. After the link between the interconnect device and the first packet forwarding device is established, the first packet forwarding device receives a command from the interconnect device requesting the types of data that are pending on the first packet forwarding device. Responsive to the command, the first packet forwarding device transmits a 'menu' including information indicating the availability of one or more types of data that are awaiting transmission to the interconnect device. An 'order' is received by the first packet forwarding device from the interconnect device. The order includes information identifying a type of data being requested by the interconnect device. Responsive to the order, the first packet forwarding device transmits a message which contains data of the type identified by the order to the interconnect device.

Protocol for communicating data between packet forwarding devices via an

A repeater in a LAN maintains a count of collisions and retransmission attempts for each node coupled to the repeater since that node's last successful packet transmission. The count is used to prioritize which of the nodes involved in a subsequent collision will be allowed to continue transmitting. The time at which data packets from the nodes arrive at the repeater will vary according to the propagation delay attributed to the varying lengths of the communication medium between each of the nodes and the repeater. For the repeater to arbitrate among the nodes that begin transmitting, it is useful to receive the data packets from each node at the same time. The repeater automatically equalizes the transmission delay. The repeater buffers the data packet received from each node until sufficient time has elapsed to begin receiving a data packet from each node that is attempting to transmit a data packet during the current arbitration interval. For each node, the repeater maintains a slot time counter. The backoff time following a collision is measured in increments of slot time, so using the slot time counter for a node allows the repeater to predict when it will receive a data packet from a node that is currently backed off. When a node has an opportunity to attempt transmitting a data packet at each slot time, the repeater determines if that node is going to attempt to transmit a data packet before deciding which node will be allowed to transmit a data packet.

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San Jose, CA, United States of America

Herb Schneider