Ciena Corporation

Cisco Technology, Inc.

Optical Networks, Inc.

Oni Systems Corp.

Rohit Sharma

Larry R McAdams

Holden Jessup

Hon Wah Chin

Denis Zaccarin

Jayakumar Jayakumar

Frederic Mathieu

Swaminathan Sundararaman

Mandar S Joshi

Francois Edouard Tallet

Ashish Gupta

Sridhar Alagar

Brian Pheiffer

John Sandoval

Gokul S Tirumalai

Rainer Iraschko

Naresh Sharma

Chang Ahn

Virendra Patel

Padavala Rao

Stephane St Laurent

Raja Rangarjan

In one embodiment, in response to receiving a topology change notification at a network bridge having ports identified as either a network port or an edge port, address learning may be disabled on the network bridge. Once address learning is disabled, an association of all entries of a forwarding table of the network bridge having addresses previously forwarded on a particular network port of the network bridge may be changed to forward those addresses on all network ports of the network bridge (e.g., flooding the frames not addressed to edge ports on all network ports only). Subsequently, address learning may be enabled on the network bridge, thus repopulating the network port entries of the forwarding table in response to the topology change.

Optimized flush operation in response to topology changes for spanning tree protocols

In one embodiment, configuring one or more ports of an access layer entity connected to a distribution layer entity to suppress one or more network topology change information from transmitting to the distribution layer entity of a data network, detecting a state change to a forwarding state on the one or more ports of the access layer entity, and configuring the one or more ports of the access layer entity in the data network connected to the distribution layer entity to transmit a predetermined data packet on the one or more ports of the access layer entity whose state has changed to the forwarding state are provided.

Minimizing spanning-tree protocol event processing and flooding in distribution networks

A method is described that resets a first count and resets a second count if a first transmission unit is recognized as being within a new measurement time window. The first transmission unit has a size. The method also increments the first count by the first transmission unit size and by the size of each subsequent transmission unit that is received within the new measurement time window after the first transmission unit&#x2014;so long as the first count does not exceed a maximum allowable value for the first count. The method also checks if a maximum value for the second count is exceeded if it is incremented by a second transmission unit size. The second transmission unit is received within the measurement time window. The check is in response to a determination that the first count would have exceeded the first count maximum allowable valuable if the first count were incremented by the second transmission unit size.

Method and apparatus for input policing a network connection

Techniques for providing normal operation and service restoration capability in the event of failure of terminal equipment or transmission media in a heterogeneous network, such as a hybrid network containing single- and multi-wavelength lightwave communications systems. An optical switching node (OSN) is placed at each node in the ring network to provide the required connections between various fibers and terminal equipment, but having switch states that allow signals on the protection fibers to bypass the terminal equipment at that node. Ring-switched signals propagate around the ring on protection fibers without encountering the terminal equipment at the intervening nodes. To the extent that the protection fiber links between any given pair of nodes are incapable of supporting all the relevant communication regimes, such links are modified to provide such support.

Method and apparatus for operation, protection, and restoration of heterogeneous optical communication networks

A statistics data collection mechanism for distributed, high-speed data processing environments is described. According to one embodiment, an update message containing statistics data related to a data packet carried along a virtual connection is assembled and the update message is then transmitted to a statistics collection engine for further processing. According to another embodiment, the update message is received from one or more processing devices, and multiple counters are then updated to store the statistics data.

Statistics data collection mechanism for distributed, high-speed data processing environments

A distribution pattern is established to distribute multilink frame relay (MFR) fragments. The distribution pattern includes a sequence of link entries associated with links in a link bundle. A number of link entries in the distribution pattern is determined by dividing a total link speed of the link bundle by a minimum possible link speed supported by a system. Each link entry is placed in the distribution pattern when the associated link is capable of transmitting a current fragment in a fastest transmit time. The fastest transmit time is determined based on the link speed of the link and a transmit time for the link to transmit other fragments previously allocated to that link. The fragments are distributed to the links in the link bundle according to the distribution pattern from a first link entry to a last link entry in the distribution pattern. The distribution pattern is repeated after the last link entry.

Method for multi-link load balancing to improve sequenced delivery of frames at peer end

In a ring having first and second adjacent nodes, and two fibers carrying information between the first and second nodes, the first fiber carries information in one direction, while the second fiber carries information in another direction. Each fiber includes wavelength capacity allocated to working and protection traffic. The working and protection wavelength capacities in the first fiber are respectively assigned to first and second disjoint sets of wavelengths, while the working and protection wavelength capacities in the second fiber are respectively assigned to the second and first disjoint sets of wavelengths.

Wavelength and filter arrangement for WDM networks

A system for use in a bi-directional path switched ring network for detecting a failed optical path and establishing a protection path so as to allow signals from the failed optical path to be re-routed via the protection path is provided. According to one aspect of the system, upon detecting a failure relating to an optical path, the destination node generates a connection request message for transmission to the source node. The connection request message is passed to the source node via one or more intermediate nodes, if any. Each intermediate node examines the connection request message accordingly reserves the requisite wavelength from the protection capacity so as to allow signals from the failed optical path to be re-routed. Upon receiving the connection request message, the source node readies its switching equipment to re-route signals from the failed optical path and generates an acknowledgment message and propagates it back to the destination node via the intermediate nodes. The intermediate nodes and the destination node, upon receipt of the acknowledgement message, also ready their respective switching equipment to carry the re-routed signals via the previously reserved wavelength from the protection capacity. According to another aspect of the system, a contention resolution mechanism is provided to resolve contending connection request messages received at a node requesting the same wavelength to be reserved from the protection capacity for different failed optical paths. A message format is used for the connection request which allows the connection request message to include information relating to the type of failure experienced by a failed optical path and other priority data. Such information is then used by a node to determine priority between two contending connection request messages.

Method and system for bi-directional path switched network

A network element (NE) in a communications network decodes a data stream received over a communication link. Upon synchronization with the data stream, the NE determines a performance metric for the link based on a number of transmission code violations. In response to the performance metric exceeding a predetermined threshold, the NE commands the selection of a different link to carry the data stream via a switch signal. The switching or rerouting of signals may occur between a single pair of NEs (e.g., point-to-point span) or in a more complex topology having a plurality of interconnected NEs.

Network performance monitoring and restoration based on transmission code violations

Method and apparatus for operation, protection and restoration of heterogeneous optical communication networks

Method and apparatus for operation, protection, and restoration of

Techniques for providing normal operation and service restoration capability in the event of failure of terminal equipment or transmission media in a heterogeneous network, such as a hybrid network containing single- and multi-wavelength lightwave communications systems.

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Sunnyvale, CA, United States of America

Rohit Sharma