Dynamic fair queuing to support best effort traffic in an ATM network
AssigneeInternational Business Machines Corporation
InventorsJean Calvignac, Daniel Orsatti, Fabrice Verplanken
Life of this patent
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Abstract
A flow control apparatus implemented in a virtual path ATM communication system comprising a plurality of nodes interconnected by physical links which comprise virtual paths including a plurality of virtual channels. A connection between two nodes is defined as the combination of a physical link, a virtual path, and a virtual channel. Connections are shared between a reserved bandwidth service and a best effort service. ATM data cells conveyed on said best effort service are routed from node to node by analyzing their virtual connection identifier. Queues, allocated as needed from a pool of free queues, are used to store all incoming ATM data cells having the same virtual channel identifier.
Claims8
In a data communication network having a plurality of nodes interconnected by links, each of said links being identified by a link identifier and supporting a plurality of virtual paths, each of the virtual paths being identified by a virtual path identifier VPi and further supporting a plurality of virtual channels, each of said channels being identified by a virtual channel identifier VCi, the combination of said link, virtual path and virtual channel identifiers defining a virtual connection over which data cells can be conveyed between nodes, each of said data cells including a virtual path identifier CVPi and a virtual channel identifier CVCi, a flow control apparatus located at a node in the network and comprising:
- a pool of free queues for storing incoming data cells;
- identifying means for reading the CVPi and CVCi identifiers for each incoming data cell;
- means for performing a look up operation based on the CVPi and CVCi identifiers to determine whether a queue already exists for the virtual connection identified by said CVPi and CVCi identifiers;
- means responsive to a determination that no queue exists for said virtual connection for allocating a queue from said pool of free queues and for storing cells received on said virtual connection in said allocated queue;
- and
- means responsive to a determination that a queue already exists for said virtual connection to store cells received on said virtual connection in the already existing queue.
Dependencies are inferred from the claim text.