초록 ▼

A transparently-bridged wide area network connecting Ethernet/IEEE 802.3-based local area networks uses redundant proxy devices on each LAN for internetwork communications. The proxy devices on a given LAN, implemented as data link switching (DLSw) devices, identify amongst each other a master proxy

A transparently-bridged wide area network connecting Ethernet/IEEE 802.3-based local area networks uses redundant proxy devices on each LAN for internetwork communications. The proxy devices on a given LAN, implemented as data link switching (DLSw) devices, identify amongst each other a master proxy device for mediating services to be provided to an end station on the local area network. Each proxy device connected to the local area network sends a request to the identified master proxy device in response to detecting a frame transmitted by an end station on the local area network, for permission to establish a circuit connection for transfer of the frame via a wide area network. The master proxy device, based on prescribed criteria, selects one of the proxy devices for transferring the frame, and sends a grant response to the selected proxy device. The master proxy device sends an "inuse" response as a denial response to the other proxy devices indicating the corresponding request has been denied, thereby avoiding contention for proxy services. Databases within the proxy devices track the request, grants, and denials to minimize generation of repeated requests. The inventory of granted requests may also be modified based on failures detected within the master proxy device, or any proxy device having received grants. Hence, redundant DLSw-type proxy devices may be implemented on a local area network while maintaining a stable and a robust communications system.

대표청구항 ▼

[ What is claimed is:] [1.] A method of intercommunication between first and second local area networks via a wide area network, the method comprising:identifying a master proxy device from among at least two proxy devices coupled to the first local area network;receiving by the proxy devices a fram

[ What is claimed is:] [1.] A method of intercommunication between first and second local area networks via a wide area network, the method comprising:identifying a master proxy device from among at least two proxy devices coupled to the first local area network;receiving by the proxy devices a frame transmitted by a first end station onto the first local area network for transfer to the second local area network via the wide area network;sending a request to the master proxy device, by at least one of the other proxy devices on the first local area network, to transfer the frame to the second local area network;outputting a response by the master proxy device onto the first local area network to the at least one other proxy device indicating whether the corresponding request is granted; anddetermining whether a circuit connection may be initiated via the wide area network for transfer of the frame, by the at least one other proxy device, based on the corresponding response received from the master proxy device.