Giochi cooperativi per incentivare la collaborazione tra operatori

Giochi cooperativi per incentivare la collaborazione tra operatori Internet per l’offerta di nuovi servizi a valore aggiunto Stefano Seccia in collaborazione con J. -L. Rougiera, A. Pattavinab, M. Mycekc , M. Pioroc , A. Tomaszewskic a Telecom Paris. Tech, France; b Politecnico di Milano, Italy; c Warsaw University of Technology, Poland Corso di Teoria dei Giochi, Applicazioni Collegio Borromeo, Università di Pavia, 29 -30 Marzo 2010, Pavia

Rationales the big picture page 1 INFRES

COORDINATED Peering ROUTING (recall) page 2 INFRES

Current inter-domain routing current practice across top-tier interconnections Current BGP routing in the Internet core • Routing decisions based on unilateral costs • Lack of routing coordination, especially on peering links • Routing on peering links is increasingly unstable Change of colour = change of top-50 carrier border (10 min sampling) - High risk of congestions route deviations - OBJECTIVE: control the coupling between IGP and BGP routing ISP international ISP regional page 3 INFRES ISP national ISP regional ISP regional

Coordinated inter-provider BGP routing a game-theoretic approach Club. MED: Coordinated Multi-Exit Discriminator game • selfish game + dummy game + congestion game - Is a potential game: Nash equilibrium minimum of the potential function • IGP cost variations potential min. threshold enlargement of the Nash set • Coordination policies to select efficient multipath equilibrium sets Tp page 4 INFRES

5 Toward an extended peering framework • Each peer sees the extended peering frontier as a unique frontier such as for the classical peering • Routing decision: where to route the egress aggregate flow from its community toward the other communities of the other peers • The receiving peer deaggregates the flow: one toward its destination, one transiting toward another peer folllowing BGP • Gd is now characterized by ingress costs and transit costs page 5 INFRES

6 An extended peering game example page 6 INFRES

COOPERATIVE CONNECTION-ORIENTED ROUTING page 7 INFRES

Cooperative provider alliances architecture and protocol extensions Inter-provider MPLS/G-MPLS provisioning • Definition of the functional architecture • An end-to-end network service as result of service elements composition page 8 INFRES

Cooperative provider alliances AS-level routing Proposition of an AS-level source routing algorithm • Requirements: 1. Policy routing 2. Directional metrics 3. Pre-computation 4. Multipoint routing 5. Route diversity page 9 INFRES

COOPERATION INCENTIVES FOR INTEGRATED RESOURCE RESERVATION page 10 INFRES

How to incent provider cooperation? a Shapley value perspective Modeling of cross-provider resource optimization • Application of cooperative game theory to motivate it - Shapley value: strategic weight of the importance of each player in each possible (sub)coalition • As income distribution incentive for cross-provider added-value services - Accounting for how much each provider has reserved resources for other providers’ services The Shapley value can be used to assign the payoff (income) of a player (provider) as function of its marginal contribution to the coalition. It is calculated as follows: 1. consider all the possible permutations of the providers 2. for each per mutation and each provider, calculate the marginal contribution that the provider grants if it joins the coalition formed by the predecessor providers 3. for each provider, calculate the average of its marginal contributions on all the permutations. page 11 INFRES

Static reservation in Provider Alliances a Shapley value computation example Shapley value computation • Starting with per-destination link reservation levels - How much each provider in each ordered subcoalition can guarantee? What is its marginal contribution in terms of bw reservation? - The weighted average is the SV p 1 = 0. 5, p 2 = 0. 25, p 3 = 0. 25 page 12 INFRES

Static reservation in Provider Alliances a Shapley value perspective Modeling of cross-provider resource optimization • Abstract representation of reservation levels • From router link level toward AS-level page 13 INFRES

Static reservation in Provider Alliances a Shapley value perspective Modeling of cross-provider resource optimization • Application of cooperative game theory to motivate it - Shapley value: strategic weight of the importance of each player in each possible (sub)coalition • As income distribution incentive for cross-provider added-value services - Accounting for how much each provider has reserved resources for other providers’ services Per inter-AS link and per-flow bandwidth reservation levels page 14 INFRES i = injected t = terminated tr = transit

Static reservation in Provider Alliances Shapley value properties contextualized • Symmetry - If a provider reserve as much bandwidth as another provider for a flow, both should get the same amount • Efficiency - All the revenues related to a service are shared among the providers that reserved the resources for that service • Null player - If a provider reserve no bandwidth for a tunnel service, it will get zero • Anonymity - The name of the provider does not affect the value imputation • Additivity - The combination of more games (more tunnels) result in the sum of the single Shapley values page 15 INFRES

Static reservation in Provider Alliances a Shapley value-based revenue distribution Fair multi-provider schemes for cost/revenue sharing • Extension for all per-destination flows page 16 INFRES

Related publications S. Secci, J. -L. Rougier, A. Pattavina, M. Mycek, M. Pioro, A. Tomaszewski, " Connection-oriented Service Management in Provider Alliances: a Shapley Value Perspective", submitted to Euro-NF 5 th Int. Workshop on Traffic Management and Traffic Engineering for the Future Internet, 7 -8 Dec. 2009, Paris, France. M. Mycek, S. Secci, M. Pioro, J. -L. Rougier, A. Tomaszewski, A. Pattavina, "Cooperative Multi-Provider Routing Optimization and Income Distribution", in Proc. of 2009 7 th Int. Workshop on the Design of Reliable Communication Networks (DRCN 2009), 25 -28 Oct. 2009, Washington, USA. Interesting overview of Shapley value applications S. Moretti, F. Patrone, Transversality of the Shapley value, Top, 16, no. 1, 1 -41, July 2008. Technology framework paper R. Douville, J. -L. Le Roux, J. -L. Rougier, S. Secci, "A Service Plane over the PCE Architecture for Automatic Multi-Domain Connection-Oriented Services", IEEE Communications Magazine, Vol. 46, No. 6, June 2008. Ph. D dissertation Stefano Secci, Multi-provider Service and Transport Architectures, Politecnico di Milano and Télécom Paris. Tech - ENST, Dec. 2009 page 17 INFRES

This is the end… QUESTIONS? page 18 INFRES