MIT Department of Electrical Engineering & Computer Science

A Stateless Core Approach for Scalable Internet Services

Ion Stoica
Carnegie Mellon University

Thursday, April 6, 2000
4:15 PM (refreshments 4:00)
Room NE43-518
EECS Special Seminar

Abstract

As the Internet evolves into a global communication infrastructure, there is a growing need to support powerful and flexible services such as traffic management and quality of service (QoS). Over the past decade, two classes of solutions have emerged: those maintaining the stateless property of the original Internet architecture (e.g., Differentiated Services), and those requiring a new stateful architecture in which routers maintain per-flow or per-connection state (e.g., Tenet, Integrated Services). While stateless solutions are more scalable and robust, stateful solutions can provide services with higher flexibility, utilization, and assurance levels.

In this talk, I will present a novel technique and a network architecture that bridge this long-standing gap between stateless and stateful solutions. The key idea behind this technique, called Dynamic Packet State (DPS), is that, instead of having routers maintain per-flow state, packets carry this state. Based on DPS, we have developed a network architecture called Stateless Core (SCORE) in which core routers do not maintain any per-flow state. Yet, by using DPS to coordinate actions of edge and core routers along the path traversed by a flow, distributed algorithms can be designed to emulate the behavior of a broad class of stateful networks in SCORE networks. We have developed complete solutions including architectures, algorithms and implementations which address three of the most important problems in today's Internet: providing QoS guarantees, differentiated QoS, and traffic management.