On the Flow-level Dynamics of a Packet-switched Network

TL;DR

This paper explores the relationship between packet-level and flow-level dynamics in packet-switched networks, highlighting how separate models have traditionally provided distinct insights into network performance and congestion control.

Contribution

It offers an integrated analysis of flow-level and packet-level models, bridging the gap between these two perspectives in network performance understanding.

Findings

Packet-level models focus on physical layer scheduling.

Flow-level models emphasize end-to-end congestion control.

The paper proposes a unified framework linking both models.

Abstract

The packet is the fundamental unit of transportation in modern communication networks such as the Internet. Physical layer scheduling decisions are made at the level of packets, and packet-level models with exogenous arrival processes have long been employed to study network performance, as well as design scheduling policies that more efficiently utilize network resources. On the other hand, a user of the network is more concerned with end-to-end bandwidth, which is allocated through congestion control policies such as TCP. Utility-based flow-level models have played an important role in understanding congestion control protocols. In summary, these two classes of models have provided separate insights for flow-level and packet-level dynamics of a network.