1 / 20

ISPs as Nodes or Sets of Links?

ISPs as Nodes or Sets of Links?. 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). Outline. Motivation Contract- S witching Architecture

maxime
Download Presentation

ISPs as Nodes or Sets of Links?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ISPs as Nodes or Sets of Links? Praveen K. Muthuswamy Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute In collaboration with KoushikKar, Aparna Gupta (RPI) Hasan T. Karaoglu, Murat Yuksel (UNR)

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

  3. Motivation • 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. Internet Routing Limitations • 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. Related Work • 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 • XiaoweiYang, David Clark, and Arthur Berger, NIRA: A new inter-domain routing architecture. IEEE/ACM Transactions on Networking, 15:775–788, 2007. • E. Mannie. Generalized mplsarchitecture, RFC 3945

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

  7. Internet Traffic Engineering using CSP • 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

  8. Notations • - 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. Optimal TE formulation (1/2) • Maximum Throughput Routing Throughput Edge-to-edge flows Capacity constraints Flow-conservation constraints

  10. Optimal TE formulation (2/2) • Minimum Delay Routing • Vxy(f) is a convex-cost with each router-to-router link. Consider M/M/1 delay cost. • Minimum Bandwidth Routing

  11. Frameworks for Benchmarking • 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

  12. Simulation Results • 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

  13. Maximum Throughput • Average throughput on 50 random topologies

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

  15. Minimum Bandwidth • Average total bandwidth on 50 BRITE topologies

  16. Distributed TE solution • 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. Numerical Study • 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

  18. Average convergence time • 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. Conclusion • 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

  20. Thank You !! Questions ?

More Related