Alcatel Canada Inc.

Alcatel-Lucent Canada Inc.

Alcatel Lucent

Alcatel

Newbridge Networks Corporation

Jason T Sterne

David Walter Carr

Dion Pike

Robert Elliott Robotham

Steve Driediger

Andre Poulin

Denny L Lee

Denny L S Lee

Robert Morton

Steven Douglas Margerm

Paul Nadj

Randall Allan Law

Brent Duckering

Shay Nahum

Thomas Edward Davis

Peter Donovan

Stanko Vuleta

Tom Edward Davis

Nutan Behki

Predrag Kostic

James Michael Schriel

Ken Dubuc

Joey Chow

Adrian Grah

John C Fischer

Jerome Cornet

Joey M W Chow

Richard Grieve

Larry Friesen

Mark Thibodeau

Aaron Maxwell MacDonald

Robert John Johnson

John William Galway

Bin Du

Roxana Hamedani

Pual Nadj

Joey M Chow

Michael Wayne Mitchell

Herman Ho Ming Liu

Allan Randall Law

Mark Jason Thibodeau

A method for incorporating a queuing device as a lossless processing stage in a network device in a communications network, comprising: monitoring a depth of a queue in the queuing device, the queue for receiving packets from an upstream device within the network device, the queuing device acting as a discard point by discarding packets when the queue is full; and, if the depth passes a predetermined threshold, sending a message to the upstream device to reduce a rate at which packets are sent to the queuing device to prevent the queue from filling and thereby preventing packet discarding and loss by the queuing device.

Method and system for using a queuing device as a lossless stage in a network device in a communications network

A method and apparatus for communicating data packets according to classes of service is described. One or more service interfaces are coupled to a plurality of transport interfaces. The service interfaces carry packets having multiple classes of service, while each of the plurality of transport interfaces carries packets of a single class of service. A differentiated services codepoint profile is associated with each service interface and maps a differentiated services codepoint value of a data packet to a class of service and a drop precedence. The data packet is assigned to a transport interface based on its class of service and its drop precedence. Other factors, such as the destination of the data packet may be considered when assigning the data packet to a transport interface. Data packets from different transport interfaces are preferably enqueued in different queues of a destination service interface.

Method and apparatus for communicating data packets according to classes of service

The invention provides a system and method of controlling timing of release of traffic for a communication switch. The traffic originates from at least one source, is directed to a common ingress point of the switch and is directed to a common egress point in the switch. The egress point has a maximum egress transmission rate. The traffic has at least one datastream. Each datastream has a requested transmission rate. The method comprises, for each datastream, establishing a maximum cell release rate such that a sum of each of the maximum cell release rate does not exceed the maximum egress transmission rate and utilizing the maximum cell release rate to govern release of local traffic in the datastream from the ingress point.

System and method for providing gaps between data elements at ingress to a network element

A method and apparatus are provided for maintaining access control lists (ACLs) within TCAM on a line card in a data packet router, the rules being applied to incoming data packets. Each interface may be associated with multiple ACLs, and multiple interfaces may be associated with single shared ACLs. The shared ACLs include rules applicable to more than one interface. Other ACLs are specific to a particular interface. When searching for a rule to apply to an incoming data packet, the filter searches both the specific ACL and the shared ACLs associated with the interface over which the data packet arrived. Using the shared ACLs, duplication of common rules is reduced, thereby reducing the total number of rules stored on the line card and saving memory storage space. The invention is also applicable to sets of rules other than ACLs.

Access control listing mechanism for routers

The packet rate limiting method and system is used for detecting and blocking the effects of DoS attacks on IP networks. The method uses an ACL counter that stores an action parameter in the first 3 most significant bits and uses 13 bits as a packet counter. A rate limit is enforced by setting the packet counter to an initial value, and resetting this value at given intervals of time. The action parameter enables the ACL to accept or deny packets based on this rate limit. If the number of packets in the incoming flow saturates the packet counter before the reset time, the packets are denied access to the network until the counter is next reset. The denied packets may be just discarded or may be extracted for further examination.

Metering packet flows for limiting effects of denial of service attacks

A method for identifying faulty modules within telecommunication devices, such as ATM switches, involves generating and attaching verification codes, such as a CRC or checksum codes, to data packets at an upstream location determining the integrity of the verification codes at each of multiple downstream location within a telecommunication device; and signaling an error condition where a corrupted data packet has been detected. A verification code may be written to a field of a data packet which is not used while the packet is in transit through the telecommunication device.

Method and apparatus for providing integral cell payload integrity verification and detecting defective modules in telecommunication devices

A method and apparatus for buffering data units in a communication switch that allows for configurable monitoring of the buffer contents is presented. Such an apparatus includes a context table that stores a plurality of independent group identifiers for each connection. Although the group identifiers may include a partition group identifier and a loss group identifier that is dependent on the partition group identifier, additional group identifiers are included in the context table for each connection that are independent of other group identifiers in the context table. Such a context table may be dynamically reconfigured in order to group connections for buffer monitoring operations related to congestion detection, traffic shaping, and data admission with respect to buffering. When a data unit is received corresponding to a particular connection, the context table is referenced to retrieve the set of group identifiers corresponding to that connection. As a cell is stored in the buffer, count values corresponding to at least some of the group identifiers included in the set of group identifiers for that connection are incremented. Similarly, when data is dequeued from the buffer for forwarding, the set of group identifiers for that particular data unit is determined and the counters corresponding to at least some of those groups are decremented. As such, the count value corresponding to each of the groups can be referenced to determine the number of data units corresponding to that group that are currently stored within the buffer.

Method and apparatus for monitoring buffer contents in a data communication system

The backpressure flow control mechanism is widely used in telecommunications network. Actions of the flow control scheme are not instantaneous in that latency always exists between action and reaction, resulting in a flow control round trip time. This flow control round trip time causes ambiguity in determining the amount of traffic in transit. The invention monitors the amount of traffic which is on the way toward the queue during the past period of the round trip time, thus eliminating the ambiguity. A more precise control of traffic flow is possible, realizing reduction of storage space in the queue by one half. In one embodiment, the invention keeps a historical record of flow control signals sent back during the most recent flow control round trip time.

Backpressure history mechanism in flow control

A method and apparatus for sending packets from traffic flows to queues in a network element is provided. Each traffic flow has a packet size parameter indicating a sizing constraint for its packets. The method includes the step of grouping the traffic flows into groups utilizing the packet size parameter of each traffic flow. The method further includes the step of sending packets only from traffic flows of one group to at least one designated queue. Traffic flows of the one group are identified utilizing the packet size parameter of each traffic flow.

System and method for reassembling packets in a network element

A multi-protocol switch that supports both ATM and IP traffic and method for use is presented. The multi-protocol switch associates certain input connections, as identified by virtual path identifier/virtual connection identifier (VPI/VCI), with either IP or ATM traffic. When the connection identifier for a cell received indicates that the cell is an ATM cell, the multi-protocol switch forwards the cell through the switch, where the forwarding is based on the connection identifier for the cell. If the connection identifier for a cell indicates that the cell is IP traffic, the cell is stored with other cells included in the IP packet to which the cells correspond within the ingress line card of the switch. The destination address included in the packet is used to determine a forwarding decision for the cells included in the packet. After at least partial reassembly, the packet is segmented and forwarded through the switch based on the forwarding decision determined from the destination address.

Multi-protocol switch and method therefore

A method and apparatus for supporting virtual path aggregations (VPAs) in a communications network is presented. To establish a VPA in the network, a request for the VPA is received, where the request indicates a desired data path between a source switch and a destination switch. Based on the request, it is determined whether or not there are resources available to create the VPA. If the resources are present, the VPA is created. Once created, connections may be established using the VPA by first determining whether or not the needs of the connection are satisfied by the capabilities of the VPA. If the VPA is capable of supporting the connection, the connection is established using the VPA. If the VPA is not capable of supporting the connection, the connection may either be established using other resources or rejected.

Method and apparatus for virtual path aggregation (VPA) connection admission control (CAC)

Data traffic such as cell streams in an ATM communication network frequently contain data destined for multiple output ports having different transmission data rates. In order to accurately schedule such traffic a clocking signal unique to each output data rate is required. This invention provides systems and methods for generating the necessary clock signals utilizing a single timing reference.

Timing reference for scheduling data traffic on multiple ports

Apparatus and method for implementing virtual path aggregation (VPA) of underlying virtual connections at a switching node of a connection based communications network. A multi-service traffic shaping module (MTSM) at the switch implements algorithms to aggregate the VC and VP connections onto the aggregate VP by representing an aggregate VP as a plurality of circular linked lists or loops and assigning each VC connection to a link or element in the circular linked lists according to traffic descriptors. Weighting factors are used as between loops to dynamically select the next loop to service. Once this loop is chosen, the next VC to be serviced is identified by examining the circular linked list structure.

Virtual path aggregation

A method for identifying faulty modules within telecommunication devices, such as ATM switches, involves generating and attaching verification codes, such as CRC or checksum codes, to data packets, such as ATM cells, at an upstream location, determining the integrity of the verification codes at each of multiple downstream location within a telecommunication device; and signaling an error condition where a corrupted data packet has been detected. A verification code may be written to a filed of a data packet which is not used while the ATM cell is in transit through the telecommunication device, thereby identifying a faulty module device without adversely affecting throughput.

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Ottawa, Canada

Jason T Sterne