Tussle in cyberspace: Defining tomorrow ’ s internet (2002) D.Clark, J. Wroclawski, K. Sollins & R. Braden Presented by: Gergely Biczok (Slides in courtesy of: Ao-Jan Su)

Introduction Different Internet players have interests that may be adverse to each other, and they vie to favor their particular interests. This is called TUSSLE. Accommodating this tussle is crucial to the evolution of the network ’ s technical architecture.

Tussle Examples The different players –Music lovers vs. the rights holders –People who want to talk in private vs. the government that want to tap their conversation –ISPs must interconnect but are sometimes fierce competitors New requirements on the internet’s technical architecture –Motivate new design strategies to accommodate the growing tussle

Structure of this paper Difference between the mechanisms and society. Outline some proposed design principles Discussion of some tussle spaces

Natures of engineering and society Engineers: solve the problems by designing mechanisms with predictable consequences. Society: dynamic management of evolving and conflicting interests. Personal example: Network Neutrality Measurement project

Internet players Users You and me Commercial ISPs AT&T, Comcast Private sector network providers Governments Intellectual property rights holders Content providers and higher level services Google, Amzaon, Ebay

Principles Highest-level: design for variations in outcome Be flexible Tussle in the design, not by violating the design Two specific principles: Modularize the design along tussle boundaries Use modularity to manage complexity Like reusable software components Design for choice Users ’ choice of mail systems ISPs has a different view (filtering/redirecting port 25)

Implications from principles Choice often requires open interfaces Allow competition among algorithms Tussles often happen across interfaces Example: BGP connects competitive ISPs It matters if the consequence of choice is visible Public vs. secret (routing arrangement among ISPs) 2007: Comcast ’ s choice of poisoning BitTorrent (loss of prestige) Tussles have different flavors Not certainly adverse interests, but Different interests (sender & traffic carrier)  pricing problem

Implications from principles (Cont.) Tussles evolve over time It is a multi-round game : BitTorrent got filtered : Encryption implemented : Updated filters: based on flow-patterns and peer-tracker communication : TCP-over-UDP, dropping RST, VPNs 5. … No such thing as value-neutral design No perfect design decisions. Don ’ t assume that you design the answer You are designing a playing field, not the outcome.

Tussle spaces (1) Economics Providers tussles as they compete and consumers tussle with providers to get the service they want at a low price Our principle of design of choice into mechanism is the building block of competition Customers must have the ability to choose (switch) providers freely.

Examples Provider lock-in from IP addressing Incorporate mechanisms that make it easy for a host to change address Since 2002: Change you cell phone carrier without changing your cell phone number Value pricing Divide customers based on their willingness to pay Pay higher rate to run a server at home

Examples (continue) Residential broadband access Municipal deployment of fiber as a platform for competitors Competitive wide area access Support source routing with a recognition of the need for payment Pay toll Since 2002 research on Internet economics shows interest of T1 ISPs contact end-users directly (larger revenue) Network Anti-Neutrality: ISPs want to milk content providers

Tussle spaces (2) Trust Users do not trust each other Users don ’ t trust parties they actually want to talk to Explicit choice of trusted 3 rd party Less and less trust to their own software Non-technical solution seems feasible Design for choice: privacy vs. security Identity “ Not forbidden is permitted ” vs. anonym users

Tussle space (3) Openness The openness to innovation that permits a new application to be deployed Economical motivations Proprietary interfaces give market power Vertical integration by ISPs Bundling infrastructure and services Somewhat restricted but better QoS Separate Tussle of vertical integration Tussle of sustaining innovation

Old principles End to end arguments Still valid, but need a more complex articulation Network could provide more information (ECN, QoS) Motivate ISPs to modify routers We need the tussle of competition! Separation of policy and mechanism Mechanism defines the range of “ policies ” No pure separation of policy from mechanism BUT: do isolate tussle free regions of the system Fixed-points

Conclusion and effect Do not deny the reality of the tussle, but recognize our power to shape it. A different way of thinking for system designers 2006: NSF FIND initiative starts Clean-slate redesign of the Internet Economics Trust This paper is a very important precursor Great effect