Application-level control of IP networks: IP beyond the internet

The Internet today can be compared to a road system that is freely accessib le to everyone with a car. Traffic jams are the inevitable consequence. Tra ditional switched telephone networks, on the other hand, can be compared to railways, which have limited access to tracks, resold (or even reserved) s eats, and limited or nonexistent traffic jams. Delays and cost are predicta ble. The Internet, with its increasing importance for telecommunications an d business, can no longer afford unpredictable traffic jams. The convergenc e of voice and data on a single packet-based network imposes stringent requ irements for quality of service (QoS) stability, billing, and security. The refore, the Internet must conform to basic rules that govern traditional te lecommunication infrastructures as well as accommodate new, flexible busine ss models beyond the present free-for-all that address regional market diff erentiation and local regulation. This paper describes a network architectu re that allows today's Internet to evolve in a way that permits more flexib le business models and differentiated policies. Networks are modeled as sep arate domains, each with its own set of transport services, policies, and Q oS mechanisms within an autonomous business framework. This architecture co mbines elements of both telecommunication and data networks: it is Internet protocol (IP) based but without the business constraints imposed by the In ternet today.