Contract-Switching: Value Flows in Inter-Domain Routing

1. Contract-Switching: Value Flows in Inter-Domain Routing Murat Yuksel University of Nevada – Reno Reno, NV Aparna Gupta, Koushik Kar, Shiv Kalyanaraman Rensselaer Polytechnic Institute Troy, NY Project Website http://www.cse.unr.edu/~yuksem/contract-switching.htm Or google “Contract Switching”

2. Motivation Implied Challenges • Current architectural problems: • Users cannot express value choices at sufficient granularity – only at access level • Providers do not have economic knobs to manage risks involved in • QoS investments • inter-ISP relationships flexibility in time: forward/option pricing flexibility in space: user-defined inter-domain routes capability to provide e2e higher quality services money-back guarantees, risk/cost sharing

3. Inter-domain struggles… When crossing domains, all bets are off.. End-to-end QoS or reliability requires assurance of single-domain performance, i.e., “contract”s efficient concatenation of single-domain contracts Inter-domain routing needs to be aware of economic semantics contract routing + risk management We address translation of these struggles to architectural problems 3

4. ISP B ISP A ISP B ISP C routable datagrams ISP A ISP C ISP B contracts overlaid on routable datagrams ISP A ISP C Contract-switching: A paradigm shift… e2e circuits Circuit-switching Packet-switching Contract-switching

5. Contract Link • An ISP is abstracted as a set of “contract links” • Contract link: an advertisable contract • between peering/edge points • with flexibility of advertising different prices for edge-to-edge (g2g) intra-domain paths capability of managing value flows at a finer granularity than point-to-anywhere deals

6. How to achieve e2e QoS? • Contract Routing – spatial composition of e2e contracts • Compose e2e inter-domain “contract paths” over available contract links satisfying the QoS requirements • Calculate the contract paths by shortest-path algos with metrics customized w.r.t. contract QoS metrics • Two ways: • link-state contract routing at macro time-scales • path-vector contract routing at micro time-scales • Monitor and verify that each ISP involved in an e2e contract path is doing the job • Punish the ISPs not doing their job, e.g. as a money-back guarantee to the others involved in the e2e contract path

7. Link-State Contract Routing: Macro-level, proactive Most cost-efficient route ISP B 2 ISP A 1 4 User X 3 ISP C 5 Max QoS route Global Internet 2008

8. Path-Vector Contract Routing: Micro-level, on-demand, reactive • User initiates… • User X wants to know if it can reach 5 with 10-30Mb/s for 15-45mins in a $10 budget [5, 10-30Mb/s, 15-45mins, $10] [5, A, 1-2, 15-30Mb/s, 15-30mins, $8] [5, A-B, 1-2-4, 15-20Mb/s, 20-30mins, $4] ISP B path request path request 2 reply reply [A-B-C, 1-2-4-5, 20Mb/s, 30mins] 1 4 ISP A User X reply 3 ISP C path request Paths to 5 are found and ISP C sends replies to the user with two specific contract-path-vectors. Paths to 5 are found and ISP C sends replies to the user with two specific contract-path-vectors. 5 [5, A, 1-3, 5-10Mb/s, 15-20mins, $7] [A-C, 1-3-5, 10Mb/s, 15mins] Global Internet 2008

9. Path-Vector Contract Routing: Micro-level, on-demand, reactive • Provider initiates… • ISP C wants to advertise availability of a short-term contract link [C-B-A, 5-4-2-1, 20Mb/s, 30mins, $7.3+$3] [C-B, 5-4-2, 20Mb/s, 45mins, $6+$5] [C, 5-4, 30Mb/s, 45mins, $9] ISP B path announcement path announcement 2 ISP A 1 4 User X 3 ISP C path announcement 5 [C, 5-3, 10Mb/s, 30mins, $5] [C-A, 5-3-1, 5Mb/s, 15mins, $1.25+$1.2] Global Internet 2008

10. Temporal Extensions of Single-domain QoS Contracts • Bailout Forwards: on advertisable spot contracts • with flexibility of advertising different forward pricesfor g2g intra-domain paths • Forwards with provision for bailout conditioned on network status Time

11. Bailout Forward Contract • Multiple g2g Contracts • Exposed to the additional effects of other traffic flows as a result of overlapping links with other g2g overlay paths • How do we model this interaction?

12. Intensity of Overlap Link Capacity 1.5 Gbps Utilization = 10% Link Capacity 0.3 Gbps Utilization = 50% Flow1 50 mbps Flow2 100 mbps

13. BFC Performance • Can an ISP survive by applying BFC approach? • How frequent does BFC bailout? • BFC Robustness against • increasing demand? (demand) • decreasing available bandwidth? (supply) • major link failures? • How efficient is BFC pricing? • Revenue Losses

14. Simulation Results: Dynamic Demand Financial guess – Forward breakdown prob Technical guess - Bailout probability Results for five sample g2g contracts Threshold = 15th percentile IEEE IWQoS 2008

15. Simulation Results:Dynamic demand EXODUS – 372 g2g paths Mean fraction 16.4 % IEEE IWQoS 2008

16. Network Analysis: Robustness against failures EXODUS – 372 g2g paths Mean fraction 27% IEEE IWQoS 2008

17. Simulation Results:Effect of Simplified Pricing Node 5 Node 1 ABOVENET – histogram of 7 days revenue pt-anywhere pricing g2g pricing simplified g2g pricing

18. Simulation Results:Effect of Forward Pricing Node 1 ABOVENET – 40% of available capacity is contracted as “forward” pt-anywhere pricing simplified g2g pricing simplified forward g2g pricing

19. Future Work and Questions Protocol implementation and simulation of CR Balance between LSCR and PVCR ISP collaboration and competition pricing the inter-domain risk game theoretic analysis contract verification common punishment and rewarding laws Goal: more economics in inter-domain routing 19

20. THE END Thank you!