Communication system architecture and a connection verification mechanism therefor

• US 6,298,043 B1
• Filed: 03/28/1998
• Issued: 10/02/2001
• Est. Priority Date: 03/28/1998
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Mauger, Roy Harold, Cable, Julian Frank Barry, Brueckheimer, Simon Daniel
• Primary Examiner(s): VINCENT, DAVID ROBERT
• Application Number:
  US09/049,702
• Time in Patent Office: 1,284 Days
• Field of Search: 370/351, 370/352, 370/354, 370/353, 370/355, 370/356, 370/357, 370/358, 370/359, 370/360, 370/376, 370/386, 370/387, 370/388, 370/389, 370/391, 370/394, 370/395, 370/400, 370/411, 370/412, 370/419, 370/422, 370/427, 370/428, 370/431, 370/464, 370/908, 370/912, 370/914, 370/915, 370/916, 370/212, 370/229, 370/254, 370/276, 370/248, 370/230
• US Class Current: 370/248
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04L 2012/5663 Support of N-ISDN

Abstract

A communication system typically comprises a number of interconnected broadband-narrowband interfaces (304, 402-404) that together interact to provide a communication resource (400) that can support a call across the system At a time when the communication resource (or a portion thereof) is apparently in place, a terminating node of a broadband-narrowband interface sends a verify-request message (452) backwards across the communication resource. A connection broker (322), coupled to both ends of the communication resource in a particular broadband-narrowband interface (404), is aware of the issuance of the verify-request message, and is therefore able to assess and report, principally, on path connectivity of the communication resource (either within the broadband-narrowband interface or between adjacent interfaces). More particularly, the connection broker expects the arrival of a path connectivity message (454, 460) issued from an end of the broadband-narrowband network responsive to the verify-request message and, as such, can provide an appropriate report (458, 470, 480) upon the timely receipt, or not, of the path connectivity message. Indeed, the verify-request message may also function to confirm path continuity.

Claims

1. A method of verifying the path connectivity of a communication resource that supports a call between a first node and second node, the call established through a connection broker located intermediate between a call server responsible for controlling the call and a switch assembly that routes the call, and wherein the second node is separated from first node by at least one switch assembly, the method comprising the steps of:

causing the connection broker to be aware of a requirement to confirm the path connectivity of a connection between the first node and the second node;

sending, over the communication resource for the call, a path verify-request message between the first node and the second node;

detecting the path verify-request message at a respective node to which the path verify-request message was sent;

at the respective node to which the path verify-request message was sent, sending the connection broker a verify-confirm message indicating receipt of the path verify-request message over the communication resource for the call; and

at the connection broker, receiving the verify-confirm message else causing the connection broker to register a fault in the communication resource for the call.

2. The method of verifying the path connectivity of a communication resource according to claim 1, wherein the second node is a network adaptor that interfaces a broadband resource to a narrowband trunk, and the step of causing the connection broker to be aware of the requirement to confirm further includes the steps of:

having the connection broker notify the network adaptor of the requirement to send the path verify-request message.

3. The method of verifying the path connectivity of a communication resource according to claim 1, further comprising the step of:

at the connection broker and in response to receiving the verify-confirm message, sending an end-to-end confirmation message to a connection broker associated with the node from which the path verify-request message originated, the end-to-end confirmation message verifying the path connectivity of the communication resource for the call.

4. The method of verifying the path connectivity of a communication resource according to claim 3, wherein the end-to-end confirmation message is sent in-channel.

5. The method of verifying the path connectivity of a communication resource according to claim 4, wherein the end-to-end confirmation message is sent within an operation and maintenance cell.

6. The method of verifying the path connectivity of a communication resource according to claim 5, wherein the operation and maintenance cell is an F-5 cell.

7. The method of verifying the path connectivity of a communication resource according to claim 1, wherein the path verify-request message is sent in-channel.

8. The method of verifying the path connectivity of a communication resource according to claim 1, wherein path verify-request message is sent within an F-5 cell.

9. The method of verifying the path connectivity of a communication resource according to claim 1, wherein the step of causing the connection broker to be aware of the requirement to confirm is triggered by a connection broker associated with a terminating node for the call.

10. The method of verifying the path connectivity of a communication resource according to claim 1, wherein the path verify-request message is sent in a backwards direction from the second node and towards a unit originating the call.

11. The method of verifying the path connectivity of a communication resource according to claim 1, wherein the step of causing the connection broker to be aware of the requirement to confirm further includes the steps of sending a verify-confirm message to the connection broker.

12. The method of verifying the path connectivity of a communication resource according to claim 3, further including the steps of:

at the connection broker associated the node from which the path verify-request message originated, waiting a predetermined time to receive the end-to-end confirmation message; and

in the event of not receiving the end-to-end confirmation message within the predetermined time, sending a path disruption message to the call server.

13. The method of verifying the path connectivity of a communication resource according to claim 10, further including the step of providing a modified version of the path verify-request message as an output from the node to which the path verify-request message was sent.

14. The method of verifying the path connectivity of a communication resource according to claim 13, wherein the modified version includes node-specific connectivity information.

15. The method of verifying the path connectivity of a communication resource according to claim 3, wherein the end-o-end confirmation message is sent to the call server via a dedicated connection.

16. The method of verifying the path connectivity of a communication resource according to claim 1, wherein the step of detecting the path verify-request message further includes the step of using the path verify-request message to assess at least one of path integrity and path quality.

17. The method of verifying the path connectivity of a communication resource according to claim 5, wherein the operations and maintenance cell includes authentication codes.

18. The method of verifying the path connectivity of a communication resource according to claim 17, wherein the authentication includes a public key and a private key and wherein the method further includes the steps of:

decoding, by means of the public key, information signed by the private key;

ignoring the path verify-request message in the event that the step of decoding of the signed information is unsuccessful; and

ignoring the path verify-request message in the event that the information has been tampered with.

19. A communication system comprising at least one call server responsible for controlling a call supported by a communication resource between a first node and a second node, a plurality of interconnected switch assemblies responsive to the at least one call server and arranged to provide routes for the communication resource, and a plurality of connection brokers each coupled between the at least one call server and each of the plurality of interconnected switch assemblies, the system further comprising:

means for causing a connection broker to be aware of a requirement to confirm the path connectivity of a connection between the first node and the second node;

means for sending, over the communication resource assigned to the call, a path verify-request message between the first node and the second node;

means for detecting the path verify-request message at a respective node to which the path verify-request message was sent;

in the respective node to which the path verify-request message was sent, means for sending the connection broker a verify-confirm message indicating receipt of the path verify-request message over the communication resource for the call; and

in each connection broker, means for receiving the verify-confirm message to confirm path connectivity of the communication resource between the first node and the second node else means for causing the connection broker to register a fault in the communication resource assigned to the call.

20. The communication system of claim 19, further including means for determining at least one of a path integrity and a quality assessment, said means for determining operationally responsive to receipt of said path verify-request message.

21. The communication system of claim 19, wherein the second node is a network adaptor that interfaces a broadband resource to a narrowband trunk and wherein each connection broker contains means for notifying the network adaptor of the requirement to send the path verify-request message.

22. The communication system of claim 21, further means for sending an end-to-end confirmation message to a connection broker associated with the node from which the path verify-request message originated, the end-to-end confirmation message verifying at least the path connectivity of the communication resource for the call.

23. The communication system of claim 21, wherein the end-to-end confirmation message, the verify-request message and the verify-confirm message are sent within an operations and maintenance cell, and preferably within an F-5 cell.

24. The communication system of claim 19, wherein the path verify-request message is sent in a backwards direction from the second node to the first node and in a direction towards a subscriber unit originating the call.

25. The communication system of claim 21, wherein the network adaptor includes means for sending a verify-confirm message to the connection broker to make the connection broker aware of the requirement to confirm.

26. A connection broker for coupling between a call server and a switch assembly having a first node and a second node and wherein the call server is arranged to control a call supported by a communication resource established between the first node and the second node, the connection broker comprising:

means for receiving a path verify-request message emanating from the second node, which path verify-request causes the connection broker to anticipate receipt of a verify-confirm message sent from the first node;

means for registering a verify-confirm message to confirm at least path connectivity of the communication resource between the first node and the second node; and

means for causing the connection broker to register a fault in the communication resource assigned to the call in the event that the means for registering fails to detect the verify-confirm message.

27. The connection broker of claim 26, further including means for notifying the second node of the requirement to send the path verify-request message.

28. The connection broker of claim 26, further including means for sending an end-to-end confirmation message.

29. The connection broker of claim 28, further comprising means for packaging the end-to-end confirmation message within an operations and maintenance cell, and preferably within an F-5 cell.

30. The connection broker of claim 28, further comprising means for receiving the end-to-end confirmation message and means, in response to the receipt of the end-to-end confirmation message, for substantiating path integrity of the communication resource to the call server.