US 5,473,604 AGranted

Method for avoiding node overload in a packet switching network

AssigneeAT&T Corp.

InventorsDiana L. Lorenz, Robert F. Shaw, Ronald A. Spanke

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Abstract

A system and method that controls node congestion in a packet switching network by allowing the congested node to seize control of transmission on the packet switching network and not relinquishing control until it has drained its buffer of the backlog of packets. In response to the node's buffer reaching a predetermined occupancy level, the node requests from the network's arbiter for exclusive transmission rights on the network. When the node receives transmission rights, the node continues to process packets in the buffer. When the occupancy of the buffer reaches a second predetermined threshold, the node releases the transmission right, and thus permits other nodes to transmit packets to it (and to other nodes) again.

Claims11

Dependent claims

A method for controlling node congestion in a packet switching network, said packet switching network having a plurality of nodes capable of transmitting and receiving packets on said network, said packet switching network having an arbitration mechanism to determine which one of said plurality of nodes may have transmission rights on said network at a given time, said plurality of nodes includes a first node having a receive buffer for receiving packets at the transmission rate of said network, said first node removing and processing packets from said receive buffer at a rate lower than said transmission rate of said network, said method comprising the steps of:

said first node monitoring the occupancy of its respective receive buffer;
when the occupancy of said receive buffer in said first node exceeds a first predetermined threshold, said first node requests said arbitration mechanism for transmission right on said network;
upon being granted said transmission right, said first node holding onto said transmission right while continuing to process packets from said receive buffer;
and
upon reaching a second predetermined occupancy threshold in said receive buffer, said second predetermined occupancy threshold being less than or equal to said first predetermined threshold, said first node releasing said transmission right.

2 more elements

Dependencies are inferred from the claim text.