Browse Prior Art Database

Duplicate Bridge Number Detection

IP.com Disclosure Number: IPCOM000044489D
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Sy, KK: AUTHOR

Abstract

This article provides a technique for verifying that different bridges on a common loop are not identified by the same bridge numbers and for assuring that there is only one limited broadcast path among parallel bridges. The technique requires a bridge to start a verification process when it is inserted into a ring. The inserting bridge sends a bridge verification frame to all other bridges on the same ring. A timer is started when the frame is sent. The destination address (DA) field of this frame contains the functional address that is assigned to the bridge. This frame includes the identification number of the inserting bridge, station address, its corresponding ring numbers and forwarding limited broadcast capability.

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Duplicate Bridge Number Detection

This article provides a technique for verifying that different bridges on a common loop are not identified by the same bridge numbers and for assuring that there is only one limited broadcast path among parallel bridges. The technique requires a bridge to start a verification process when it is inserted into a ring. The inserting bridge sends a bridge verification frame to all other bridges on the same ring. A timer is started when the frame is sent. The destination address (DA) field of this frame contains the functional address that is assigned to the bridge. This frame includes the identification number of the inserting bridge, station address, its corresponding ring numbers and forwarding limited broadcast capability. In addition, the inserting bridge sets the end delimiter indicating (EDI) bit, the frame copy indicating (FCI) bits and the address recognized indicator (ARI) bit to an "off" state. Upon the return of the transmitted frame the inserting bridge will examine the EDI bit, the ARI bit, and the FCI bits.

If these bits are in the off state, this indicates that there is no other bridge in the same ring, the timer is stopped, and the process is completed. If there are other bridges on the same ring, the first downstream bridge copies the frame and turns on the ARI and FCI bits. All other bridges that are further downstream, seeing that the control bits are on, ignore the bridge verification frame. In addition to copying the frame, the first downstream bridge generates a new bridge verification frame. The new frame includes the information of the original frame plus its own parameters (that is, its bridge number, station address, corresponding r...