Telecommunications network distributed restoration method and system

• US 6,512,740 B1
• Filed: 11/03/1998
• Issued: 01/28/2003
• Est. Priority Date: 03/12/1997
• Status: Expired due to Term

• Current Assignee: Alcatel Network Systems India Limited (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Badt, S. Hal Sr., McGlade, Bryan J., Alagar, Sridhar, Ellefson, Frederick R., Brimmage, Ashley W., Baniewicz, Paul T.
• Primary Examiner(s): NGUYEN, STEVEN H D
• Application Number:
  US09/185,190
• Time in Patent Office: 1,547 Days
• Field of Search: 370/216-228, 370/527, 370/529, 370/242-252, 370/255, 370/522, 370/496, 370/506, 370/537-538, 370/254, 340/825.01, 340/2.7, 714/1, 714/2, 714/4
• US Class Current: 370/216
• CPC Class Codes: H04J 2203/006 Fault tolerance and recovery
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04Q 3/0062 Provisions for network management
• CPC Class Codes: H04Q 3/0079 involving restoration of networks, e.g. disaster recovery, self-healing networks

Abstract

A network wherein a plurality of links connects a plurality of nodes such as cross-connects in a communication circuit network with paths interconnecting the nodes, and with there being spare capacity between a sufficient number of nodes to accommodate at least some rerouting of traffic immediately upon detection of a break in a traffic span in the network so as to restore circuit continuity within a predetermined maximum time using an improved failure detection, isolation, and recovery

Claims

1. A method for identifying a pair of neighboring nodes in a telecommunications network having at least one distributed restoration subnetwork, comprising:

identifying a level of quality associated with each of a plurality of spare links;

selecting one of the spare links based upon the level of quality associated with each of the plurality of spare links;

constructing a first C-bit keep alive message for a first node in a neighboring node pair connected by the selected spare link;

embedding the first C-bit keep alive message within the C-bit of a first DS-3 signal; and

transmitting the first DS-3 signal from the first node to a second node in the neighboring node pair over the selected spare link, wherein the first C-bit keep alive message identifies the first node to the second node.

2. The method of claim 1, further comprising:

receiving the first DS-3 signal at the second node; and

processing the first DS-3 signal to identify the first node from the first C-bit keep alive message to the second node.

3. The method of claim 1, further comprising:

constructing a second C-bit keep alive message for the second node in the neighboring node pair;

embedding the second C-bit keep alive message within the C-bit of a second DS-3 signal; and

transmitting the second,DS-3 signal from the second node to the first node in the neighboring node pair over the selected spare link to identify the second node to the first node.

4. The method of claim 3, wherein the first node has a first identification designation and the second node has a second identification designation, and further wherein the first C-bit keep alive message contains the first identification designation and the second C-bit keep alive message contains the second identification designation.

5. The method of claim 4, wherein the first identification designation includes a first node identifier, a first node port number, a first node a wide area network address, and a first node “

I am custodial”

indicator in the first C-bit keep alive message, and wherein the second identification designation includes a second node identifier, a second node port number, a second node a wide area network address, and a second node “

I am custodial”

indicator in the second C-bit keep alive message.

6. The method of claim 1, wherein the network comprises a plurality of neighboring node pairs, and further wherein a C-bit embedded keep alive message is sent between each pair of neighboring nodes connected by a spare link.

7. The method of claim 1, wherein each node has an identification designation, and further wherein each C-bit embedded keep alive message includes the identification designation for the node from which the C-bit embedded keep alive message originates.

8. The method of claim 7, wherein each identification designation further comprises a node identifier, a port number, a wide area network address, and an “

I am custodial”

indicator for the node from which the C-bit embedded keep alive message originates.

9. The method of claim 8, wherein each DS-3 signal travels in-band.

10. The method of claim 1 further comprising constructing a local network topology at the second node.

11. A telecommunications network comprising a plurality of nodes interconnected by a plurality of links, and a distributed restoration subnetwork, comprising:

a first node having a first unique identifier;

a second node having a second unique identifier;

a first spare link connecting the first node to the second node, wherein the first spare link is selected from a plurality of spare links based upon a level of quality associated with each of the plurality of spare links; and

a DS-3 signaling channel within the first spare link, wherein the first node and second node are operable to send a DS-3 signal having a keep alive message embedded within a C-bit to one another.

12. The network of claim 11, wherein a DS-3 signal from the first node contains the first unique identifier and a DS-3 signal from the second node contains the second unique identifier.

13. The network of claim 12, wherein the first node is operable to send a first node DS-3 signal to the second node over the first spare link to identify the first node to the second node, and wherein the second node is operable to send a second node DS-3 signal to the first node over the first spare link to identify the second node to the first node.

14. The network of claim 11, wherein the network further comprises a plurality of neighboring node pairs, and further wherein each pair connected by one of the plurality of spare links is operable to send a plurality of DS-3 signals with a C-bit embedded keep alive messages to each other.

15. The network of claim 14, wherein each node has a unique numerical identifier, and further wherein each keep alive message comprises the unique numerical identifier for the node from which the DS-3 signal is generated.

16. The network of claim 15, wherein each unique numerical identifier includes a node identifier, a port number, a wide area network address, and an “

I am custodial”

indicator for the node from which the DS-3 signal is generated.

17. The network of claim 11, wherein each node has a unique numerical identifier, and further wherein each keep alive message comprises the unique numerical identifier for the node from the keep alive message originators.

18. The network of claim 11, wherein the keep alive message includes a node identifier, a port number, a wide area network address, and an “

I am custodial”

indicator.

19. The network of claim 11, wherein all DS-3 signals travel in-band.

20. A method for identifying a pair of neighboring nodes in a telecommunications network:

having at least one distributed restoration subnetwork, comprising;

identifying a level of quality associated with each of a plurality of spare links;

selecting one of the spare links based upon the level of quality associated with each of the plurality of spare links;

constructing a first keep alive message for a first node in a neighboring node pair connected by the selected spare link;

embedding the first keep alive message within a C-bit of a first DS-3 signal; and

transmitting the first DS-3 signal from the first node to a second node in the neighboring node pair over the selected spare link, wherein the first keep alive message identifies the first node to the second node.

21. The method of claim 20, further comprising:

receiving the first DS-3 signal at the second node; and

processing the first DS-3 signal to identify the first node from the first keep alive message to the second node.

22. The method of claim 21, further comprising:

constructing a second keep alive message for a second node in the neighboring node pair;

embedding the second keep alive message within a C-bit of a second DS-3 signal; and

transmitting the second DS-3 signal from the second node to the first node in the neighboring node pair over the selected spare link to identify the second node to the first node.

23. The method of claim 20, wherein the DS-3 signal containing the keep alive message is transmitted prior to a network fault.