The Internet's simple best-effort packet-switched architecture lies at the core of its tremendous success and impact. Today, the Internet is firmly a commercial medium involving numerous competitive service providers and content providers. However, current Internet architecture neither allows (i) users to indicate their value choices at sufficient granularity, nor (ii) providers to manage risks involved in investment for new innovative quality-of-service (QoS) technologies and business relationships with other providers as well as users. Currently, users can only indicate their value choices at the access/link bandwidth level, not at the routing level. End-to-end (e2e) QoS contracts are possible today via virtual private networks, but with static and long-term contracts. Further, an enterprise that needs e2e capacity contracts between two arbitrary points on the Internet for a short period of time has no way of expressing its needs.

We propose an Internet architecture that allows flexible, finer-grained, dynamic contracting over multiple providers. With such capabilities, the Internet itself will be viewed as a “contract-switched” network beyond its current status as a “packet-switched” network. A contract-switched architecture will enable flexible and economically efficient management of risks and value flows in an Internet characterized by many tussle points. We view “contract-switching” as a generalization of the packet-switching paradigm of the current Internet architecture. For example, size of a packet can be considered as a special case of the capacity of a contract to expire at a very short term, e.g., transmission time of a packet.