AUTOMATIC NETWORK TOPOLOGY IDENTIFICATION BY NODES IN THE NETWORK

• US 20100124176A1
• Filed: 07/01/2009
• Published: 05/20/2010
• Est. Priority Date: 03/03/2000
• Status: Active Grant

• Current Assignee: ADTRAN Incorporated (ADTRAN Holdings, Inc.)
• Original Assignee: ADTRAN Incorporated (ADTRAN Holdings, Inc.)
• Inventors: FAN, JASON C., BANNAI, VINAY K., JOGALEKAR, PRASAD P.
• Granted Patent: US 7,916,723 B2
• Time in Patent Office: Days
• US Class Current: 370/250
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 2101/672 Short addresses
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 61/2596 Translation of addresses of the same type other than IP, e.g. translation from MAC to MAC addresses

Abstract

An automatic network topology identification technique is described herein. Each node in the network periodically or constantly transmits its unique address to its neighboring node. Once a node receives a different message from its neighbor, the node identifies a topology change in the network. In one embodiment, a current topology is associated with a session number. When a change in the topology is detected, the detecting node increments the session number and broadcasts the change in topology. The other nodes, detecting the changed session number, now know that there has been a change in the network. In response, the nodes in the network modify routing tables and other information stored at the node related to the topology. In one embodiment, the technique is used to reassign shortened addresses to each device on the network to support a dual-addressing mode of the network. The dual addressing mode substitutes reduced-length addresses (referred to as short addresses) for standard addresses (referred to as long addresses) for traffic whose source or destination is internal to a given virtual network topology. The required length of short addresses used for a given virtual topology is dependent on the number of devices reachable within the topology.

Claims

1. A method performed by a communications network, said network comprising interconnect nodes, said method comprising:

monitoring by a first node a message from a neighboring node identifying attributes of said neighboring node;

detecting a change in said message from a previous message so as to identify a change in attributes of said neighboring node, corresponding to a change in said network; and

communicating to other nodes in said network by said first node said change in said topology.