CALL SETUP SYSTEMS AND METHODS USING DYNAMIC LINK TAGGING AND OVERBOOKING OF LINKS IN MULTI-DOMAIN TRANSPORT NETWORKS

• US 20140205278A1
• Filed: 03/04/2013
• Published: 07/24/2014
• Est. Priority Date: 01/21/2013
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: Prakash, Anurag, Chhillar, Mohit, Kakkar, Vikas, Juneja, Kapil
• Granted Patent: US 9,172,658 B2
• Time in Patent Office: Days
• US Class Current: 398/5
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 47/724 at intermediate nodes, e.g. resource reservation protocol [RSVP]
• CPC Class Codes: H04L 47/728 for backup paths

Abstract

Call setup methods in a multi-domain network and a multi-domain network use dynamic link tagging and/or overbooking of External Network-Network Interface (ENNI) links. Thus, improved call setup systems and methods include two approaches to improve upon the responsiveness of the network for connection setups including bandwidth reservation in optical networks using “dynamic link tags” and link overbooking in optical networks based on a greedy approach. The bandwidth reservation and the link overbooking can be utilized together or separately to improve call setup. Advantageously, the improved call setup systems and methods can provide a generic bandwidth reservation mechanism, such as in Automatically Switched Optical Network (ASON) networks, to overcome the limitation of ENNI in concurrently updating the abstract link bandwidth and thereby improving the responsiveness of the network.

Claims

1. A call setup method in a multi-domain network, comprising:

receiving, at a routing controller or a central server, an abstract link configuration request between two border nodes in a domain of the multi-domain network with a plurality of parameters associated therewith;

determining a path for an abstract link in the domain based on the abstract link configuration request;

generating a unique tag identifier for the determined path;

flooding the determined path in the domain with the associated unique tag identifier; and

creating the abstract link on the determined path such that the determined path is reserved based on the plurality of parameters.

2. The call setup method of claim 1, further comprising:

tracking the abstract link at the routing controller or the central server.

3. The call setup method of claim 1, further comprising:

determining the path for the abstract link in the domain based on the abstract link configuration request as either an explicit link or an implicit link;

for the explicit link, determining the path based on an explicit list of nodes in the domain; and

for the implicit link, computing the path based on the plurality of parameters.

4. The call setup method of claim 1, further comprising:

receiving a bandwidth reservation requirement between the two border nodes; and

if the bandwidth reservation requirement comprises link bandwidth reserved on the determined path, computing a path for the bandwidth reservation requirement using only links reserved with the unique tag identifier.

5. The call setup method of claim 1, wherein the path comprises a working path, and further comprising:

determining a protect path for the abstract link in the domain based on the abstract link configuration request as either an explicit link or an implicit link

flooding the determined protect path in the domain with the associated unique tag identifier; and

creating the abstract link on the determined protect path such that the determined protect path is reserved based on the plurality of parameters.

6. The call setup method of claim 4, further comprising:

responsive to the working path being down, restoring the working path to the determined path using the same associated unique tag identifier;

finding a new protect path between the two border nodes;

responsive to finding the new protect path, deallocating the unique tag identifier from the working path and assigning the unique tag identifier to the new protect path.

7. The call setup method of claim 4, further comprising:

periodically checking the determined protect path;

if the determined protect path is down, finding a new protect path between the two border nodes; and

responsive to finding the new protect path, deallocating the unique tag identifier from the determined protect path and assigning the unique tag identifier to the new protect path.

8. The call setup method of claim 1, further comprising:

operating an external network-network interface (ENNI) link connected to one of the two border nodes in an overbooked manner.

9. The call setup method of claim 8, wherein the overbooked manner comprises:

responsive to a path message requested bandwidth on the ENNI link and responsive to bandwidth being unavailable on the ENNI link for the path message, sending the path message with a blank upstream label and c-type (virtual time slot);

responsive to a reservation (RESV) message for the requested bandwidth, checking again if bandwidth is available on the ENNI link; and

if bandwidth is available when the RESV message is sent, selecting the available bandwidth for the RESV message.

10. The call setup method of claim 9, wherein the overbooked manner is operated within Automatically Switched Optical Network (ASON) as defined in G.8080/Y.1304.

11. A call setup method in a multi-domain network, comprising:

operating an external network-network interface (ENNI) link connected to a border node in the multi-domain network in an overbooked manner;

receiving a plurality of path requests over the ENNI link;

determining bandwidth is not available for one or more of the plurality of path requests;

for each of the one or more of the plurality of path requests, sending the path requests with blank upstream labels and a virtual time slot; and

upon receiving a reservation (RESV) message for each of the one or more of the plurality of path requests, checking again if bandwidth is available and if so, selecting the available bandwidth for the RESV message.

12. The call setup method of claim 11, wherein the overbooked manner is operated within Automatically Switched Optical Network (ASON) as defined in G.8080/Y.1304.

13. The call setup method of claim 12, wherein the sending the path requests comprises using a new connection type (ctype) in ASON indicative of an overbooked call.

14. The call setup method of claim 12, wherein the sending the path requests ensures calls for the one or more of the plurality of path requests are failed only when the bandwidth on the ENNI link is actually in use as opposed to reserved.

15. The call setup method of claim 11, further comprising:

receiving, at a routing controller or a central server, an abstract link configuration request between the border node and another border node in a domain of the multi-domain network with a plurality of parameters associated therewith;

determining a path for an abstract link in the domain based on the abstract link configuration request;

generating a unique tag identifier for the determined path;

flooding the determined path in the domain with the associated unique tag identifier; and

creating the abstract link on the determined path such that the determined path is reserved based on the plurality of parameters.

16. The call setup method of claim 15, further comprising:

determining the path for the abstract link in the domain based on the abstract link configuration request as either an explicit link or an implicit link;

for the explicit link, determining the path based on an explicit list of nodes in the domain; and

for the implicit link, computing the path based on the plurality of parameters.

17. The call setup method of claim 15, further comprising:

receiving a bandwidth reservation requirement between the border node and the another border node; and

if the bandwidth reservation requirement comprises link bandwidth reserved on the determined path, computing a path for the bandwidth reservation requirement using only links reserved with the unique tag identifier.

18. The call setup method of claim 15, further comprising:

determining a protect path for the abstract link in the domain based on the abstract link configuration request as either an explicit link or an implicit link

flooding the determined protect path in the domain with the associated unique tag identifier; and

creating the abstract link on the determined protect path such that the determined protect path is reserved based on the plurality of parameters.

19. The call setup method of claim 18, further comprising:

responsive to the working path being down, restoring the working path to the determined path using the same associated unique tag identifier;

finding a new protect path between the two border nodes;

responsive to finding the new protect path, deallocating the unique tag identifier from the working path and assigning the unique tag identifier to the new protect path.

20. A multi-domain network, comprising:

a plurality of domains each comprising a plurality of network elements interconnected therein;

a first border node connecting two domains of the plurality of domains via an external network-network interface (ENNI) link; and

a routing controller in one of the two domains;

wherein the ENNI link is configured to operate in an overbooked manner for calls and wherein the routing controller is configured to dynamically reserve bandwidth in one of the plurality of domains via an abstract link with a dynamic tag associated therewith.