BANDWIDTH RESERVATION REUSE IN DYNAMICALLY ALLOCATED RING PROTECTION AND RESTORATION TECHNIQUE

• US 20090141656A1
• Filed: 11/25/2008
• Published: 06/04/2009
• 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 7,957,324 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• 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 45/021 Ensuring consistency of routing table updates, e.g. by using epoch numbers
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/2596 Translation of addresses of the same type other than IP, e.g. translation from MAC to MAC addresses
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function

Abstract

The disclosed network includes two rings, wherein a first ring transmits data in a clockwise direction, and the other ring transmits data in a counterclockwise direction. The traffic is removed from the ring by the destination node. During normal operations (i.e., all spans operational), data between nodes can flow on either ring. Thus, both rings are fully utilized during normal operations. The nodes periodically test the bit error rate of the links (or the error rate is constantly calculated) to detect a fault in one of the links. The detection of such a fault sends a broadcast signal to all nodes to reconfigure a routing table within the node so as to identify the optimum routing of source traffic to the destination node after the fault.

Claims

1. A method performed by a communications network, said network comprising nodes interconnected by communication links, at least some of said nodes being connected in a ring by said links, said method comprising:

accounting for bandwidth based on source steered restoration;

reserving bandwidth on a worst-case single failure scenario basis;

avoiding redundancy in accounting for reservation protection; and

applying traffic configuration matrices to determine span loading.