Operator directed routing of connections in a digital communications network

• US 6,697,329 B1
• Filed: 05/27/1999
• Issued: 02/24/2004
• Est. Priority Date: 05/28/1998
• Status: Expired due to Term

• Current Assignee: Alcatel USA Resources Incorporated (Nokia Corporation)
• Original Assignee: Alcatel Canada Inc. (Nokia Corporation)
• Inventors: McAllister, Shawn, Veeneman, Ron, Tooker, Mark
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): SCHULTZ, WILLIAM C
• Application Number:
  US09/321,195
• Time in Patent Office: 1,734 Days
• Field of Search: 370/217, 370/218, 370/230, 370/231, 370/235, 370/236, 370/237, 370/238, 370/355, 370/389, 370/392, 370/393, 370/395, 370/396, 370/397, 370/399, 370/400, 370/401, 370/409
• US Class Current: 370/235
• CPC Class Codes: H04L 2012/562 Routing
• CPC Class Codes: H04L 2012/5621 Virtual private network [VPN]; Private-network - network-interface (P-NNI)
• 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 43/0811 by checking connectivity
• CPC Class Codes: H04L 45/10 Routing in connection-oriented networks, e.g. X.25 or ATM
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: Y04S 40/00 Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them

Abstract

A virtual circuit whose path across a network is specified by a human operator (hereinafter operator directed route or ODR VC) is established by manually provisioning a preferred path for the connection, including a source node, destination node, and intermediate nodes or subnetworks therebetween. The source node creates a call setup message which is signalled along the preferred path, whereby the intermediate nodes along the preferred path establish the bearer channel cross-connects. The operator also specifies a re-muting scheme for the ODR VC in the event the preferred path is blocked or a link subsequently fails. The re-routing scheme includes one of (a) the preferred path only; (b) at least one manually provisioned alternate path; and (c) any available path. The ODR VC provides the benefit of a permanent virtual circuit (PVC) in terms of the ability to consciously route a connection with the benefit of a soft permanent virtual circuit (SPVC) or switched virtual circuit (SVC) in terms of the capability to efficiently re-route connections by the network as opposed to a central management authority.

Claims

1. A method of establishing a connection between a source network element and a destination network element in a communications network, the source network element being associated with a path selection algorithm for identifying network path elements that define the said connection, the method comprising:

(a) providing an operator selected preferred routing indication to the source network element, the preferred routing indication defining at least one preferred network path element of the said connection located between the source network element and the destination network element;

(b) providing an operator selected re-routing indication, the re-routing indication defining instructions for re-establishing the connection in the event at least one preferred network path clement defined by the preferred routing indication becomes unavailable for sustaining the said connection; and

wherein the preferred routing indication is used to establish the said connection instead of corresponding network path elements identified by the path selection algorithm of the source network element.

2. The method according to claim 1, the method further including, creating a source-routed connection request message which specifies the preferred routing indication, and wherein the source-routed connection request message is signalled to the destination network element so as to establish the said connection.

3. The method according to claim 2, wherein the communications network further includes a network management element for originating the preferred routing indication, and wherein the source network element creates said source-routed connection request message.

4. The method according to claim 3, wherein said at least one network path element comprise one of:

a subnetwork;

a network node; and

a link between two adjacent network elements that are located between the source network element and the destination network element.

5. The method according to claim 4, wherein the preferred routing indication is manually predetermined.

6. The method according to claim 5, the method further including, establishing a bearer channel cross-connection on each said network path element which constitutes a network node in order to connect any two adjacent network elements of the source network element, the destination network element and any network element therebetweem which is located along network path elements that define said connection.

7. The method according to claim 5, wherein said manual predetermination of said preferred routing indication is indicated by one of:

manually entry;

manual with point and click assistance; and

automatic route generation with optional manual editing.

8. The method according to claim 6, wherein said at least one network path element includes at least one link between two adjacent network elements of the source network element, the destination network element and any network element therebetween that is located along network path elements that define said connection, and wherein the source-routed connection request message specifies the link.

9. The method according to claim 8, wherein every said two adjacent network elements which constitute network nodes and which correspond to each said link commissions a bearer channel cross-connection thereon so as to utilize each said link in establishing the connection.

10. The method according to claim 9, wherein adjacent network elements of the source network element, the destination network element and each network element therebetween which is located along network path elements that define said connection automatically select any available link in the event the preferred routing indication does not identify a link to be used therebetween.

11. The method according to claim 3, wherein the re-routing indication is stored at the source network element.

12. The method according to claim 11, wherein the re-routing indication comprises at least one alternate path indication each defining at least one network path element of the said connection located between the source network element and the destination network element, the alternate path indication not being identical to the preferred routing indication.

13. The method according to claim 12, wherein the re-routing indication comprises a direction to re-establish the connection using the preferred routing indication.

14. The method according to claim 11, wherein the re-routing indication comprises a direction to re-establish the connection selected from one of (i) using the preferred routing indication;

(ii) using at least one alternate path indication each defining at least one network path element of the said connection located between the source network element and the destination network element, each alternate path indication not being identical to the preferred routing indication;

(iii) using any possible path from the source network element to the destination network element; and

(iv) using each said alternate path indication successively if an earlier used alternate path indication becomes unavailable for sustaining said connection and, if every said alternate path indication becomes unavailable as aforesaid, then using any possible path from the source network element to the destination network element.

15. The method according to claim 14, wherein the communications network is a PNNI network and the any possible path is determined using PNNI routing techniques.

16. The method according to claim 15, wherein the source-routed connection request message is one of (i) an SPVC call setup message;

and (ii) an SVC call setup message;

which includes a designated transit list (DTL) specifying each said preferred network path element of said connection.

17. The method according to claim 16, the method further including cranking back the source-routed connection request message to the source network element for re-routing the connection in the event that any of said at least one link is inoperative during establishment of said connection.

18. The method according to claim 16, the method further including signalling the source network element to re-route the connection in the event that any of said at least one link becomes inoperative after establishment of said connection.

19. The method according to claim 1, wherein the preferred routing indication and the re-routing indication are originated externally of the source network element.

20. The method according to claim 19, wherein the re-routing indication is provided to the source network element.