Communication node, restoration method and communication network

• US 6,430,150 B1
• Filed: 05/06/1996
• Issued: 08/06/2002
• Est. Priority Date: 02/14/1996
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited, Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Fujitsu Limited
• Inventors: Kobrinski, Haim, Wu, Tsong Ho, Azuma, Mitsuhiro
• Primary Examiner(s): RAO, SEEMA SRINIVAS
• Application Number:
  US08/643,761
• Time in Patent Office: 2,283 Days
• Field of Search: 395/181, 395/182.02, 395/200.68, 395/200.69, 395/200.72, 395/200.73, 395/200.52, 370/216, 370/217, 370/221, 370/225, 370/400, 370/406, 370/410, 370/254, 370/255-256, 370/409, 370/392, 370/227, 370/228, 709/239-244, 340/825.01
• US Class Current: 370/218
• CPC Class Codes: H04L 41/0663 Performing the actions predefined by failover planning, e.g. switching to standby network elements
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04M 3/10 Providing fault- or trouble-signals
• CPC Class Codes: H04M 3/12 Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
• CPC Class Codes: H04M 3/2254 in networks
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13167 Redundant apparatus
• CPC Class Codes: H04Q 3/0079 involving restoration of networks, e.g. disaster recovery, self-healing networks

Abstract

In a telecommunication network, each node is provided with the same physical topology information relating to a physical construction of telecommunication paths included in the telecommunication network and with the same logical topology information relating to routing of telecommunication paths. When a failure occurs, restoration is effected by transmitting information relating to the failure that has occurred in the telecommunication network, throughout the network. Each node that receives the information relating to the failure determines alternative paths for bypassing the failure using the information relating to the failure, the physical topology information, and the logical topology information. Then service is switched to the alternative paths.

Claims

1. A restoration method in a telecommunication network in which each node is provided with physical topology information relating to a physical construction of telecommunication paths included in the entire telecommunication network and logical topology information relating to routing of telecommunication paths included in the entire telecommunication network, said restoration method comprising the steps of:

(a) broadcasting information relating to a failure that has occurred in the telecommunication network, throughout the network;

(b) in each node that has received said information relating to the failure, determining alternate paths for bypassing the failure using said information relating to the failure, said physical topology information, and said logical topology information; and

(c) in each node, switching services to the alternate paths determined in step (b).

2. The restoration method as claimed in claim 1, further comprising the step of:

(d) initializing the step (b) when information relating to another failure is received while the step (b) is being executed, within a predetermined guard time, and executing the step (b) again allowing for the information relating to said another failure so that most up-to-date alternate paths are determined.

3. The restoration method as claimed in claim 1, further comprising the step of:

(e) exchanging between nodes data relating to said physical topology information and said logical topology information at predetermined timings so that the nodes are always provided with the same physical topology information and the same logical topology information.

6. The restoration method as claimed in claim 1, further comprising the step of:

(d) identifying the type of failure by referring to the information relating to the failure and received by each node;

wherein

alternate path selection adapted for the type of failure identified in step (g) is employed in step (b).

4. A restoration method in a telecommunication network in which each node is provided with physical topology information relating to a physical construction of telecommunication paths included in the entire telecommunication network and logical topology information relating to routing of telecommunication paths included in the entire telecommunication network, said restoration method comprising the steps of:

(a) determining by computation in each node and storing in each node alternate paths adapted for typical failures prior to an actual failure;

(b) broadcasting information relating to a failure that has occurred in the telecommunication network, throughout the network; and

(c) in each node switching services to the alternate paths determined prior to the actual failure in step (a).

5. The restoration method as claimed in claim 4, wherein said telecommunication network is an asynchronous transfer mode network based on a concept of virtual paths, and zero-capacity alternate virtual paths are set in step (a) as the alternate paths.

7. A telecommunication node provided with physical topology information relating to a physical construction of all telecommunication paths included in the entire telecommunication network and logical topology information relating to routing of said telecommunication paths included in the entire telecommunication network, said telecommunication node comprising:

first means for broadcasting information relating to a failure that has occurred in the telecommunication network, throughout the telecommunication network;

second means for determining alternate paths for bypassing the failure using said information relating to the failure, said physical topology information, and said logical topology information; and

third means switching services in each node to the alternate paths determined by said second means.

8. The telecommunication node as claimed in claim 7, further comprising fourth means initializing a process in said second means when information relating to another failure is received while the alternate paths are being determined by said second means, within a predetermined guard time, and executing the process in said second means again allowing for the information relating to said another failure so that most up-to-date alternate paths are determined.

9. The telecommunication node as claimed in claim 7, further comprising fifth means exchanging between nodes data relating to said physical topology information and said logical topology information at predetermined timings so that the nodes are always provided with the same physical topology information and the same logical topology information.

10. The telecommunication node as claimed in claim 7, further comprising sixth means determining by computation and storing alternate paths adapted for typical failures prior to an actual failure;

wherein

the process in said second means is not executed when a typical failure occurs, and said third means is used to switch services to the alternate paths determined prior to the actual failure.

11. The telecommunication node as claimed in claim 10, wherein said telecommunication network is an asynchronous transfer mode network based on a concept of virtual paths, and zero-capacity alternate virtual paths are set by said sixth means as the alternate paths.

12. The telecommunication node as claimed in claim 7, further comprising seventh means identifying the type of failure by referring to the information relating to the failure an receive by each node;

wherein

alternate path selection adapted for the type of failure identified by said seventh means is employed by said second means.

13. A telecommunication network including telecommunication nodes each provided with physical topology information relating to a physical construction of telecommunication paths included in the entire telecommunication network and logical topology information relating to routing of telecommunication paths included in the entire telecommunication network, wherein each node comprises:

first means broadcasting information relating to a failure that has occurred in the telecommunication network, throughout the telecommunication network;

second means determining alternate paths for bypassing the failure using said information relating to the failure, said physical topology information, and said logical topology information; and

third means switching services in each node to the alternate paths determined by said second means.

14. A restoration method in a telecommunication network comprising the steps of:

(a) providing each node with similar physical topology information relating to a physical construction of telecommunication paths included in the entire telecommunication network and providing logical topology information relating to routing of telecommunication paths included in the entire telecommunication network;

(b) broadcasting information relating to a failure that has occurred in the telecommunication network, throughout the network;

(c) in each node that has received said information relating to the failure, determining alternate paths for bypassing the failure using said information relating to the failure, said physical topology information, and said logical topology information; and

(d) switching services in each node to the alternate paths determined in step (c).

15. A telecommunication node comprising:

storing means provided with physical topology information relating to a physical construction of telecommunication paths included in an entire telecommunication network and logical topology information relating to routing of telecommunication paths included in the entire telecommunication network, said informations being similar at each node in said network;

first means broadcasting information relating to a failure that has occurred in the telecommunication network, throughout the telecommunication network;

second means determining alternate paths for bypassing the failure using said information relating to the failure, said physical topology information, and said logical topology information; and

third means switching services in each node to the alternate paths determined by said second means.

16. A telecommunication network including telecommunication nodes, each said node comprising:

storing means provided with similar physical topology information relating to a physical construction of telecommunication paths included in the entire telecommunication network and similar logical topology information relating to routing of telecommunication paths included in the entire telecommunication network;

first means broadcasting information relating to failure that has occurred in the telecommunication network, throughout the telecommunication network;

second means determining alternate paths for bypassing the failure using said information relating to the failure, said similar physical topology information, and said similar logical topology information; and

third means switching services in each node to the alternate paths determined by said second means.