3Com Corporation

Sharon L Wiles

Alan R Poulter

Quang T Tran

Paul J Moran

David J Law

Christopher Alan Walker

Richard N Bayfield

David Whitfield

A connecting unit for use in a system comprising a 'stack' of network communication units having a cascade connection has three ports having lines for forwarding and receiving data packets and for forwarding and receiving control messages. The connecting unit increments a first signal value defining an identification number received by way of a control message at a first port, provides the received signal value by way of a control message to the third port and provides the incremented signal value by way of a control message to the second port. The connecting unit also receives a second signal value defining an active unit count by way of a control message at the first port and provides the second signal value, incremented or not in dependence on a control message received at the third port, in a control message at the second port. The first signal values (UnitIDs) are used to establish the numbering of the units in the stack and the second signal values are used to compute a count of the 'active' units in the stack.

Cascade architecture and operation for packet-based communication systems

A control device for a unit in a cascade connection of network units includes control logic which increments a count of active units and passes the count to the next control device. The count is initiated and terminated by an absence of control messages at the down port and up port respectively. The incremented count is passed up the cascade and a final count is passed down the cascade.

Cascade control architecture and operation for packet-based communication systems

Housing of an electronic extender

An extender for use in with a cascade stack of network devices comprises an electronic circuit which has three ports, and circuit connections coupling each of the three ports to each of the other two ports; port connectors for each port; a two-part housing of which a first part has an end wall apertured for the protrusion of a first and a second of the connectors and a second part has an end wall apertured for the protrusion of a third of the port connectors; and screw fixings for securing the housing parts together.

Network extender

Growing community of inventors

Bovingdon, United Kingdom

Sharon L Wiles