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A routing system and method are provided which use a composite cost in identifying routes. This allows a simple way of identifying the best route taking multiple metrics into account for each link simultaneously. The system allows for the inclusion of pruning constraints, and allows for various objectives such as bin packing or load balancing to be achieved.

Inventors: Byoung-Joon Lee, Sudhakar Ganti, Anand Srinivasan, Walter Joseph Carpini, Udo Mircea Neustadter, Cuong Tu Dang, Vincent Chi Chiu Wong
Original Assignee: Tropic Network Inc.
Primary Examiner: Duc Ho
Attorney: Dr. Victoria Donnelly
Current U.S. Classification: 370/238; 370/252; 370/401
International Classification: G01R031/08; H04L012/28

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Citations

Cited PatentFiling dateIssue dateOriginal AssigneeTitle
US5546379Aug 26, 1994Aug 13, 1996NEC AmericaBandwidth-on-demand remote office network apparatus and method
US6661797Feb 28, 2000Dec 9, 2003Lucent Technologies Inc.Quality of service based path selection for connection-oriented networks
US20020141345Jun 11, 2001Path determination in a data network
US20040022194Jul 30, 2003Digital Island, Inc.On-demand overlay routing for computer-based communication networks

Referenced by

Citing PatentFiling dateIssue dateOriginal AssigneeTitle
US7099277Feb 20, 2002Aug 29, 2006Mitsubishi Electric Research Laboratories, Inc.Dynamic optimal path selection in multiple communications networks
US7215644Mar 19, 2003May 8, 2007Alcatel LucentInter-domain constraint-based shortest path first technique for supporting hierarchical routing in interconnected multi-domain optical transport networks
US7257081Apr 19, 2002Aug 14, 2007Iptivia, Inc.Method and system for traffic monitoring in a packet communication network
US7324453Dec 16, 2002Jan 29, 2008Alcatel LucentConstraint-based shortest path first method for dynamically switched optical transport networks
US7403483Jun 12, 2003Jul 22, 2008NEC CorporationOptimum route calculation method and storage medium which stores optimum route calculation program
US7489638Apr 8, 2004Feb 10, 2009Alcatel-Lucent USA Inc.Scheduling with delayed graphs for communication networks
US7697437Jun 21, 2002Apr 13, 2010SK Telecom Co., Ltd.Route determining method in a multi protocol label switching network
US7974213Nov 21, 2008Jul 5, 2011AT&T Intellectual Property I, L.P.Methods and apparatus to select composite link cost-out thresholds
US7978611Sep 6, 2005Jul 12, 2011AT&T Intellectual Property I, L.P.Systems and methods to determine network routes based on transmission medium length
US8134935May 22, 2009Mar 13, 2012International Business Machines CorporationTransaction topology discovery using constraints

Claims

1. A method of performing multi-constraint routing comprising:

determining a composite cost:
description="In-line Formulae" end="lead"composite cost(link)=f(metric1, . . . , metricN) description="In-line Formulae" end="tail"

for each of a plurality of links under consideration in a network topology, the composite cost being a function f of a plurality of metrics metric1, . . . metricN for each link, where N>=2;

providing at least one pruning constraint for each link;

pruning the network topology on the basis of the at least one pruning constraints to remove at least one link from the network topology;

performing routing through the network topology from a source to a destination based on the composite costs
wherein performing routing through the network from a source to a destination based on the composite costs is conducted using only the links not pruned from the network topology.

2. A method according to claim 1 wherein the composite cost is determined according to: composite ⁢   ⁢ cost ⁡ ( link ) = ∑ i = 1 N ⁢ c i ⁡ ( metric i ) n ⁡ ( i )

where ci is a constant for the ith metric, and n(i) is an exponent for the ith metric.

3. A method according to claim 2 wherein the composite cost is determined according to:

description="In-line Formulae" end="lead"composite cost(link)=a*(1/Bandwidth)+b*Admin cost+c*Delay description="In-line Formulae" end="tail"

where metric1=bandwidth, metric2=Admin cost and metric3=delay, and wherein c1=a, c2=b, and c3=c, n(1)=−1, n(2)=1 and n(3)=1.

4. A method according to claim 1 further comprising:

for each link, at least one network node advertising the link's metrics across the network such that any node in the network may implement the multi-constraint routing.

5. A method according to claim 1 further wherein:

the composite cost increases with decreasing available bandwidth such routing is performed in a manner which promotes load balancing.

6. A method according to claim 5 further comprising:

performing the routing in a manner which promotes load balancing with demand reservation on at least one link.

7. A method according to claim 6 further comprising:

defining a respective demand threshold for at least one link representing demand reservation for the at least one link.

8. A method according to claim 7 further comprising:

computing a cost for each said at least one link as follows:
description="In-line Formulae" end="lead"if (available bandwidth
description="In-line Formulae" end="lead"cost=composite cost+very large value description="In-line Formulae" end="tail"
description="In-line Formulae" end="lead"else cost=composite cost description="In-line Formulae" end="tail"
where demand_threshold is a respective demand reservation for the link.

9. A method according to claim 8 wherein the demand_threshold is set to a first value for at least one of the links, and is set to a second larger value for at least one of the links whereby bandwidth on the at least one of the links having the first value is reserved for larger bandwidth requests.

10. A method according to claim 1 further comprising:

for each of a plurality of different traffic types, using a respective different composite cost equation for calculating the composite costs.

11. A method according to claim 10 wherein the different traffic types include video, voice and data.

12. A method according to claim 10 wherein the different traffic types include different classes of service/qualities of service.

13. A method according to claim 1 wherein:

pruning the network topology on the basis of the at least one pruning constraints to remove at least one link from the network topology is performed on an as needed basis to remove one or more links from a set of candidate links.

14. A method according to claim 13 wherein at least one constraint is used both as a pruning constraint and as a constraint used in the composite costs.

15. A method according to claim 1 wherein:

pruning the network topology on the basis of the at least one pruning constraints to remove at least one link from the network topology is performed on the entire network topology prior to performing the routing.

16. A routing system adapted to perform multi-constraint routing, the system comprising:

a topology repository adapted to store information identifying links, nodes and connections of a network

a multi-constraint router adapted to determine a composite cost:
description="In-line Formulae" end="lead"composite cost(link)=f(metric1, . . . , metricN) description="In-line Formulae" end="tail"

for each of a plurality of the links in the network topology, the composite cost being a function f of a plurality of metrics metric1, . . . , metricN for each link, where N>=2, and to perform routing through the network topology from a source to a destination based on the composite costs the routing system further comprises,

a pruning filter adapted to implement at least one pruning constraint by pruning the network topology on the basis of the at least one pruning constraint to remove at least one link from the network topology;

wherein the multi-constraint router performs routing through the network from a source to a destination based on the composite costs is conducted using only the links not pruned from the network topology.

17. A routing system according to claim 16 wherein the multi-constraint router is adapted to determine the composite cost is determined according to:

composite ⁢   ⁢ cost ⁡ ( link ) = ∑ i = 1 N ⁢ c i ⁡ ( metric i ) n ⁡ ( i )

where ci is a constant for the ith metric, and n(i) is an exponent for the ith metric.

18. A routing system according to claim 17 wherein the multi-constraint router is adapted to determine the composite cost is determined according to:

description="In-line Formulae" end="lead"composite cost(link)=a*(1/Bandwidth)+b*Admin cost+c*Delay description="In-line Formulae" end="tail"

metric1=bandwidth, metric2=Admin cost and metric3=delay, and wherein c1=a, c2=b and c3=c, n(1)=−1, n(2)=1 and n(3)=1.

19. A routing system according to claim 16 further comprising:

an input for receiving on an ongoing basis for each link, updated values for the metrics for the link.

20. A routing system according to claim 16 wherein the multi-constraint router is adapted to perform the routing in a manner which promotes load balancing.

21. A routing system according to claim 20 wherein the multi-constraint router is adapted to perform the routing in a manner which promotes load balancing with demand reservation.

22. A routing system according to claim 21 wherein the multi-constraint router is adapted to allocate at least one link to contain bandwidth reserved for higher bandwidth requests.

23. A routing system according to claim 22 wherein the multi-constraint router is adapted to compute the cost for each said at least one link as follows:

description="In-line Formulae" end="lead"if (available bandwidth

description="In-line Formulae" end="lead"cost=composite cost+very large value description="In-line Formulae" end="tail"

 else cost=composite cost

where demand_threshold is respective demand reservation for the link.

24. A routing system according to claim 16 wherein the multi-constraint router is adapted to, for each of a plurality of different traffic types, use a respective different composite cost equation for calculating the composite costs.

25. A routing system according to claim 16 adapted to prune and compute costs only for links belonging to routes in a candidate list.

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