1 / 22

Link-Level Internet Structures

Explore the economic and structural facets of internet networks, from single to multiple ISP setups. Delve into link-level structures, costs, traffic routing, and growth models, including incremental and global optimization approaches. Investigate how network models evolve with ISP expansion and the implications for service quality and market dynamics.

pfabian
Download Presentation

Link-Level Internet Structures

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. Link-Level Internet Structures Scott Schremmer and Kevin Wampler

  2. Overview • Structure of Internet not by chance • Economic factors influence structure • Two areas of focus: • Single ISP structure • Multiple ISP structure

  3. Single ISP Simulation • Focus on network topology • Internet is a graph • Nodes: points of presence • Population served • Geographic location • Edges: physical links • Bandwidth capacity • Need some economic information

  4. Link Cost • Function of distance and capacity • Two components • Cost of cable • Cost of laying cable

  5. Bandwidth Cost • Cost is per unit length cable • Linear in distance • Multiple cables linear in bandwidth • So single cable sublinear in bandwidth • We choose

  6. Traffic Routing • Assume shortest-hop • Distributed evenly amongst population • Traffic between n1 and n2:

  7. Calculating Load • Sum of traffic across link • For each node: • Compute shortest-hop routes • For each target node: • Add traffic to load on all links on route • If load exceeds capacity, excess is overload

  8. Generating Networks • Incremental Growth • Likely a reasonable model • Mimics and ISP adding new POPs • Growth of ISP matters • Global optimization • Entire network planned in advance

  9. Incremental Growth Model • Investigated by Barabasi and Albert • Link probability proportional to degree • Yields power degree distribution • Applicability is unclear • Suboptimal links chosen too often • No direct economic incentive

  10. A Better Model • New nodes added randomly • Optimal link always chosen • Provisioned so no overload • Topology depends on “optimal” • Cost of new link • Cost of new and replaced links • Overprovisioning

  11. Cost Of New Link • Light tailed

  12. Replaced Links • Very heavy tailed

  13. Overprovisioning • Close to power distribution

  14. Global Optimization • Optimize entire network • Growth does not matter • Need objective function • Minimize cost while providing good service • Depends on weighting

  15. Generating A Network • Initially Random • Use Simulated Annealing • Add a link • Remove a link • Grow a link • Shrink a link

  16. Cost/Service Emphasis cost service

  17. Degree Distributions

  18. Single ISP Conclusions • Topologies similar to reality from: • Minimizing load/link replacement with overprovisioning • Overconnection to improve service

  19. Extension to Multiple ISP’s • Consider that ISPs do not grow in a vacuum • How does model change with introduction of more ISP’s • Link level structures • Economic Choices • Router distributions and routing choices

  20. Specifics of simulation • Simulated annealing • 2 ISP annealed separately • Some number of iterations with one • Pass shared parameters (inter-isp traffic) • Recalculate parameters for annealing separately • Routing-2 models • Small ISP lets large ISP route to cities it doesn’t cover • Small ISP routes to its border

  21. 2 Internets. . .

  22. Future work • Consider evolving model • If an isp is providing better service or has lower cost increase its market share • Structures that result • Conditions for isp to survive • Stable? • Anneal together cooperatively, how different are structures • Add nodes to small network to simulate growth

More Related