Hewlett-Packard Company

Martyn J Riley

Anthony J Wiley

Roland J Burns

Message-routing apparatus is known for routing messages between a plurality of communications networks. Typically, the known apparatus comprises a respective network interface card for each communications network and a shared, processor-based, routing manager with which the cards communicate through a backplane bus system. In order to overcome the bandwidth limitations of such known apparatus, the present invention provides a local routing manager on each card and high-speed, point-to-point, links interconnecting the local routing managers in a closed loop. Each local routing manager recognizes whether a message passed to it is for outward transmission over the associated network; if this is not the case, the message is passed to the local routing manager of the next card. Any messages which the local routing managers are unable to route, are diverted to a shared routing manager.

Message-routing apparatus

A network diagnostic tool for determining the position of a workstation on a local area network (LAN) having timer and echo stations at each end of a multi-access bus. Signals from the LAN workstations propagate in both directions along the bus. When the signals are so propagated, by measuring the time delay between receipt of a data packet and its echo at the timer station, the position of the workstation along a bus can be determined in accordance with that time delay.

Growing community of inventors

Bristol, United Kingdom

Martyn J Riley