Nortel Networks Corporation

Hamid R Mehrvar

Kim Bryon Roberts

Roland A Smith

Mark Stephen Wight

Paul Warren

Xiaoming Fan

Andrew Sciascia

Accelerated protection switching in a multi-platform network switch may be achieved by allocating connectivity slots from the port cards to the switch cards for all states of a connection through the switch and forming maps of the allocations for use by the port cards and switch cards. By allocating connectivity slots to all states of the connection, the connection will not be blocked in connection with a state change. By storing the slot allocation in maps a connection state change may be implemented by the switch by causing traffic on the connection to be transported using the allocated slots. Various protection modes can use the same connectivity slots with collision avoidance via prepared maps Thus, having predefined paths via allocated slots provisioned through the network element enables the network element to switch very quickly from working to protection to comply with applicable standards and minimize disruption of network traffic.

Method and apparatus for accelerated protection switching in a multi-switch network element

A method and system for conveying an arbitrary mixture of high and low latency traffic streams across a common switch fabric implements a multi-dimensional traffic classification scheme, in which multiple orthogonal traffic classification methods are successively implemented for each traffic stream traversing the system. At least two diverse paths are mapped through the switch fabric, each path being optimized to satisfy respective different latency requirements. A latency classifier is adapted to route each traffic stream to a selected path optimized to satisfy latency requirements most closely matching a respective latency requirement of the traffic stream. A prioritization classifier independently prioritizes traffic streams in each path. A fairness classifier at an egress of each path can be used to enforce fairness between responsive and non-responsive traffic streams in each path. This arrangement enables traffic streams having similar latency requirements to traverse the system through a path optimized for those latency requirements.

Traffic switching using multi-dimensional packet classification

A high bandwidth connection is mapped through a multi-stage switch between an ingress node and an egress node via a center stage comprising M (an integer) center stage nodes. Each center stage node is connected to the ingress and egress nodes by respective links adapted to support m (an integer) respective connections. An m&times;M connection matrix of connections between the ingress node and the center stage is provided. Each column of the connection matrix contains 1&lE;j&lE;m connections between the ingress node and a respective one of the center stage nodes, and each row of the connection matrix contains 1&lE;k&lE;M connections between the ingress node and the center stage nodes. The high bandwidth connection is mapped through the multi-stage switch by layering the high bandwidth connection within the connection matrix. Thus the high bandwidth connection is divided into N segments. Each segment is mapped to a respective one of a block of N available connections within the connection matrix so that a sum of all connections between and ingress and an egress node is substantially evenly distributed across the center stage nodes of the Clos network.

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Nepean, Canada

Hamid R Mehrvar