Patent ID: 6594231
Filing Date: 2003-07-15
Classification: H04L

Abstract:
A stackable network unit including a first port and a second port, a first path for data packets from said first port to said second port, a second path for data packets from sad second port to said first port, a detector for detecting the absence of another operative unit connected to said first port to cause data packets on said second path to bypass said first port and proceed on said first path and for detecting the absence of another operative unit connected to said second port to cause data packets on said first path to bypass said second port and proceed on said second path, whereby the unit can form a ring communication system with other units, the stackable unit including configuring means which can cooperate by means of coded configuration packets with said other Units to establish a numerical ordering of the units in the ring, each such packet including fields which indicate the coded configuration nature of the packet, the status of the first port of the unit which was the source of the packet, a unit number and a device address; the unit being operative on receipt of such a packet from another unit by way of its said first port to compare the status information in the packet with the status of its own first port and depending on that comparison to generate a packet which has that unit's status and address information and a datum number or to forward the packet as received with incrementing of its unit number, the unit being further operative to determine whether it has received its own configuration packet by a comparison of the device address in the packet with its own address.