1. Overcoming the Internet Impasse through Virtualization Defense Chen, Jiazhen & Teng, Xian Yi

2. The problem we face Internet’s increasing ubiquity and centrality has brought with it a number of challenges for which the current architecture is ill-suited. To support new application –Modifications have arisen to meet legitimate needs that the architecture itself could not. However, modification serve a valuable short-term purpose But impair the long-term flexibility, reliability and manageability.

3. The Impasse Since the current architecture is not well suited to nowadays application. –WHY NOT ? –WHY NOT Design a new one? The Impasse: –Persuade ISPs to adopt a new architecture –Traditional test-beds have limitations.

4. Our Goal ACTION!To issue a call to ACTION! –Cease being satisfied with paper design that have no future. –Overcome the Impasse. To reduce the barrier to evaluate new idea in architectural design. –How to make a test that simulates the reality?

5. How to OVERCOME 3 3 separate requirements live –Easily experiment with new architectures on live traffic plausible –A plausible deployment path s. t. design can come into practice. –Comprehensively –Comprehensively proposed architectural solutions To meet these requirements Virtual Test-bed –We propose a Virtual Test-bed

6. Virtualization A high level abstraction that hides the underlying implementation details. –Let node treat an overlay as if it were the native network –Multiple overlays are simultaneously used This approach does not require universal architectural agreement –More plausible deployment.

7. Limitations of current approaches Two ways in which researchers currently experiment with new architecture: –Physical Test-beds –Overlays

8. Limitations of Physical Test-beds Production-oriented Testbed –The users have no choice about whether or not to participate in the testbed Research Testbed –Driven by synthetically generated traffic Both utilize dedicated transmission links – Involve substantial cost.

9. Advantages –Not limited geographically –Usage is voluntary –Not involve significant expenditure Drawbacks: –Overlays have been seen as a way of deploying narrow fixes to specific problems –Overlays have been architecturally tame, most typically assume IP as the architecture inside the overlay itself No dramatic architectural advancement Limitations of Overlays

10. Virtual Testbed Two basic components –Substrate Overlay Set of dedicated but multiplexed overlay nodes Amortized by concurrently running experiments –Drastically lower –Drastically lower the barrier-to-entry for individual researcher. –General Client-proxy mechanism Allows any host to opt-in to a particular experiment Treats nearby overlay node as the host’s first-hop router –Not require IP addressing Multiplexed substrate overlay and general proxy solve the barrier-to-entry and architectural limitations.

11. Virtual Testbed - 2 However there are issues to explore –To achieve sufficiently high throughput rates on PlanetLab nodes. The packet forwarding capability of nodes has physical limitation. New designed architecture may purpose to achieve higher throughput. –Virtual links cannot compete with dedicated links [QoS]

12. How the Proxy works Either return the true IP address of fake IP address –For fake IP address, the packets can be forwarded to the nearest VT node The VT node can do whatever it wants with the packet. –At the boundary of VT, VT egress node, reconverts the packet into Internet format for delivery to the server –Similar to NAT

13. Drawbacks of VT Cannot control the Quality of Service of packets traversing the virtual testbed. However, we assume –RoutingAddressing –Routing and Addressing that more urgently warrant attention and for which the virtual test bed approach is well-suited

14. Related works Part of the idea is not new –X-bone Suite of tools supports automated establishment and management of overlays. –Virtual Internet [VI] Allows multiple levels of virtualization But, it is closely tie to the current Internet architecture But different emphasis –The focus on the VT is on the virtualization of overlay nodes themselves. [X-bone vs. VT] –Aim at new architecture design. [VI vs. VT]

15. Future Plan for VT To Include a high performance backbone High-speed backbone with PlanetLab has two major advantages: –PlanetLab-based overlays serve as an access network for the backbone bring real traffic –Developing and deploying the hardware does not gate the architectural work.

16. Deployment Old story (discredited): “next generation” architecture -> validation -> magic -> adopted by ISPs, router vendors Our strategy: NGSP has new architecture -> overlay supporting it, proxy software => backwards compatible If successful, NGSP offers direct access, or competitors start adopting

17. Deployment Overlays as opportunity to radically change architecture instead of merely providing limited enhancements

18. Deployment New architecture could be supported natively Single NGSP or long-running virtual testbed Successful -> attract more users -> architecture migrates from virtual testbed to dedicated Instead of single architectural winner, might be large number of narrowly targeted overlays Prevent chaos -> coordination

19. Virtualization: Means or Ends Virtual testbed approach uses virtualization: –Overlay is qualitatively equivalent to native network, users freed from local ISP, network providers don’t need to deploy new functionality at every node –Many virtual testbeds running simultaneously, reduced barrier-to-entry

20. Virtualization: Means or Ends Means: –Architectural changes are rare –Purist view –Virtualization is means for architectural change –Architecture must have flexibility

21. Virtualization: Means or Ends Ends: –Internet changes constantly, with many coexisting components –Pluralist view –Virtualization is crucial to support many components and constant change –Flexibility is in adding or augmenting overlays

22. Virtualization: Means or Ends Don’t know which is correct, but our approach lets us find out

23. Conclusions If new architecture is promising, ISPs, router vendors will adopt No longer true, so researchers narrowed their focus -> empirical or incremental studies -> insufficient to meet new Internet requirements Through virtual testbeds, hopefully there will be new research unrestricted to incremental designs Through new deployment strategy closer to experimental methodology, raise sights of researchers

24. Oasis: An Overlay-Aware Network Stack Harsha V. Madhyastha, Arun Venkataramani, Arvind Krishnamurthy, and Thomas Anderson University of Washington and University of Massachusetts Amherst