System and method for providing service availability data for a communication network

• US 7,426,573 B2
• Filed: 12/12/2001
• Issued: 09/16/2008
• Est. Priority Date: 12/12/2001
• Status: Expired due to Fees

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Wells, Donald J., McAllister, Shawn, Dippel, Peter C.
• Primary Examiner(s): Caldwell, Andrew
• Assistant Examiner(s): Ford, Grant
• Application Number:
  US10/012,428
• Publication Number:
  US 20030110408A1
• Time in Patent Office: 2,470 Days
• Field of Search: 370/229, 370/252, 370/352, 370/356, 370/372, 370/385, 370/389, 370/395.5, 370/357, 370/397, 370/395.4, 370/409, 370/395.21, 714 1- 57, 709/223, 709/224, 709/226, 709/238
• US Class Current: 709/238
• CPC Class Codes: H04L 2012/5627 Fault tolerance and recovery
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04L 41/5016 based on statistics of service availability, e.g. in percentage or over a given time
• CPC Class Codes: H04L 43/062 related to network traffic
• CPC Class Codes: H04L 43/067 using time frame reporting
• CPC Class Codes: H04L 43/0823 Errors, e.g. transmission errors
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

The present invention provides a system and method of calculating a service disruption in a communication network comprising network elements, including nodes connected via links and at least one originating node. Each node is able to detect a failure in an adjacent network element. Upon detection of a failure, a first timestamp is generated. The detecting node generates a release signal which is transmitted, together with the first timestamp, to an originating node which releases the affected connection. The originating node establishes a new connection and initiates a new call. Upon establishing a new connection, a node affected by the failure, which forms a part of the new connection, records a second timestamp. The second timestamp is chosen to reflect, as closely as possible, the actual time of restoration of service in the network. Service disruption is measured as a difference between the first and second timestamps.

Claims

1. A method for determining an effective outage time for a connection in a switched communication network comprising a plurality of nodes interconnected by links, and wherein a source node establishes said connection between said source node and a destination node along a first route via a plurality of intermediate nodes, comprising:

said plurality of intermediate nodes monitoring said connection for faults occurring in said links, and wherein when a fault is detected on a link, a first intermediate node of said plurality of intermediate nodes, which said first intermediate node is adjacent and upstream of the link on which the fault was detected, sends a release message back to the source node requesting the source node to release said connection and establish a new connection over an alternate route to said destination node;

said first intermediate node recording a first timestamp indicating a time said fault was detected by said first intermediate node;

said first intermediate node including said first timestamp in said release message;

said source node initiating, in response to receipt of said release message, setup of said new connection rerouting traffic carried by said connection via said alternate route;

said destination node in response to establishment of said new connection sending an acknowledgement message upstream from said destination node back to said source node indicating that said new connection has been established;

generating a second timestamp upon establishment of said new connection; and

determining said effective outage time from said first and second timestamps.

2. A method as claimed in claim 1, wherein said first and second timestamps are synchronized to a common network time utilized by said switched communication network and said effective outage time is determined from a difference between said first timestamp and said second timestamp.

3. A method as claimed in claim 1, wherein said first and second timestamps are synchronized according to a local time zone associated with a common network time.

4. The method of claim 1, wherein said second timestamp is generated at said source node upon receipt of said acknowledgment message from said destination node confirming the new connection received by said source node.

5. The method of claim 1, further comprising recording additional information about said failure and transmitting said additional information to a network management station or a collection node of said switched communication network.

6. The method of claim 1, wherein said second timestamp is generated at said destination node upon receipt of a connect message from said source node and inserted in said acknowledgement message sent to said source node.

7. The method of claim 1, wherein said second timestamp is generated at said destination node in response to said destination node recognizing that said new connection is operational and said timestamp is inserted in said acknowledgement message sent to said source node.

8. A method as claimed in claim 2, wherein, said common network time is co-ordinated universal time (UTC).

9. A method as claimed in claim 3, further comprising:

converting said first and second timestamps to a common time format relating to said common network time; and

,

determining said effective outage time as a difference between said first and second timestamps as converted to said common time format.

10. A method as claimed in claim 9, wherein, said common network time is co-ordinated universal time (UTC).

11. A method of calculating an effective outage time related to establishing a new connection between an originating node and a destination node in a switched communication network comprising a plurality of nodes after a previously established connection between said originating node and said destination node via intermediate nodes has had a failure, said method comprising the steps of:

(i) an adjacent node to said failure in said previously established connection recording, in response to the detection of said failure, a first timestamp corresponding to a time of detection of said failure by said adjacent node in said previously established connection;

(ii) said adjacent node, in response to detection of said failure, transmitting said first timestamp to a control node in said switched communication network;

(iii) rerouting said previously established connection over said new connection via a different route through said switched communication network;

(iv) recording a second timestamp corresponding to a time of completion of establishment of said new connection at a node in said new connection, wherein said time of completion of establishment of said new connection comprises a time of receipt of a connect message corresponding to completion of said new connection;

(v) uploading said second timestamp to said control node; and

(vi) said control node calculating said effective outage time from said first and second timestamps.