1. 1 Praveen K. Muthuswamy Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute In collaboration with Koushik Kar, Aparna Gupta (RPI) Hasan T. Karaoglu, Murat Yukse l (UNR)

2. Motivation Contract-Switching Architecture Internet Traffic Engineering using Contract-switching Numerical study and Benchmarking Distributed TE Solution Contributions and Future work 2

3. Attain high-efficiency inter-domain TE Numerous methods for intra-domain TE Inter-domain TE involves many factors ranging from technology to economics and policy Current Inter-domain TE techniques are constrained to outbound traffic load balancing Cooperative inter-domain traffic engineering among neighboring ISPs is necessary

4. ISP is abstracted as a single node or as a set of nodes (in case of multiple ASes) Node abstraction simplifies inter-domain routing Loss of path selection and flexibility beyond shortest- path routing in terms of AS hops. Sufficient flexibility at the routing level is crucial for TE

5. Link-state mechanisms to inter-domain routing K. Levchenko, G. M. Voelker, R. Paturi, and S. Savage. Xl: an efficient network routing algorithm. In Proc. SIGCOMM, 2008. Pathlet Routing abstracts ISP as virtual nodes Scott Shenker, P. Brighten Godfrey, Igor Ganichev, and Ion Stoica, Pathlet routing. Proc. SIGCOMM, 2009. Inter-AS source routing and GMPLS Xiaowei Yang, David Clark, and Arthur Berger, NIRA: A new inter-domain routing architecture. IEEE/ACM Transactions on Networking, 15:775–788, 2007. E. Mannie. Generalized mpls architecture, RFC 3945

6. Contract-Switching Paradigm for Internet value flows and risk management, Yuksel et al. 2008 ISP is abstracted as a set of contract links Contract link – Advertisable contract between edge nodes (peering points) of an ISP 6 Network Core accessed only by contracts Customers Edge Router Edge Router Edge Router Edge Router Edge Router Edge Router Stations of the provider computing and advertising local prices for edge-to- edge contracts. 30Mbps, 45 min, $9

7. Each contract link follows a single, fixed intra-AS path End-to-end flows are optimally split along contract links Optimal inter-domain traffic engineering, but simple intra- domain routing 7

8. - Bandwidth capacity of router-to-router link - Physical links used to construct edge-to-edge link - Total traffic at edge router for destination - Flow on the contract or peering link

9. Maximum Throughput Routing 9 Capacity constraints Flow-conservation constraints Edge-to-edge flows Throughput

10. Minimum Delay Routing V xy (f) is a convex-cost with each router-to-router link. Consider M/M/1 delay cost. Minimum Bandwidth Routing 10

11. Global Optimum (OPT) – Complete Internet topology without abstractions (optimal inter and intra-domain routing) BGP framework – Least ISP hops for inter-domain and OSPF/RIP for intra-domain 11

12. Random topology Inter-domain and Intra-domain are random BRITE topology BRITE model for inter-domain Rocketfuel Topologies (ABILENE and GEANT) for intra-domain GTITM topology GTITM model for inter-domain Rocketfuel Topologies (ABILENE and GEANT) for intra-domain 12

13. Average throughput on 50 random topologies 13

14. Delay on Sample Random topology and Sample BRITE topology 14

15. Average total bandwidth on 50 BRITE topologies

16. Derived using the gradient descent approach to penalized objective function Traffic rate variables for each destination at each edge- link Updating of traffic rates requires only local information Gradient projection method for AS j involves projection on, the intra-domain capacity region Gradient projection method for e-edge links requires the congestion along the link and local communication between the end nodes

17. Generate Internet topologies according to BRITE Size of each AS is 10 routers Obtain ratio of converged cost to optimum cost Both average and maximum ratio is close to 1 Converged cost of the proposed TE solution is close to the optimum 17 Number of ASes102030 Average1.00391.00571.0059 Maximum1.00461.011.0093

18. 18 Convergence if cost does not vary beyond 0.5% Convergence time seems to increase sub-linearly with number of ASes, and number of destinations

19. Contract link abstraction provides significant improvement in routing performance over BGP Close to the best achievable performance Link abstraction is good for inter-domain traffic engineering Developed distributed TE solution based on gradient descent and studied its performance numerically 19

20. Thank You !! Questions ?