Patent ID: 6539020
Filing Date: 2003-03-25
Classification: H04L

Abstract:
A bridge device for connecting a plurality of self-contained communication networks around which data is transmitted in frames which include control information defining at least the identity of a destination for data in the frame, each network having at least one end station, the bridge device comprising a corresponding plurality of data coupling means for connection to respective networks, each said data coupling means including receive and transmit interfaces for respectively receiving data from and transmitting data onto the connected network; common storage means connected to all said data coupling means for receiving data being transmitted from one network to another; and control means for controlling the routing of data through the bridge device via said common storage means, wherein said control means responds to the arrival of a source route broadcast frame from one network by:i) causing the frame to be stored in said common storage means; and ii) instructing each said data coupling means to transmit the source route broadcast frame onto its network, by supplying the address of the stored frame to said data coupling means, and wherein each said data coupling means is responsive to said instruction to modify the fame, prior to transmission, by adding at least the identity of a network onto which the frame is to be transmitted, and wherein said control means is adapted to place the instruction in a header prepended to the frame in said common storage means, said data coupling means being adapted to remove the prepended header prior to transmission and to respond to the instruction in the prepended header.