Document Type

Other

Publication Date

5-22-2002

Abstract

The focus in Active Queue Management (AQM) research has been on FTP-type traffic that is long-lived, insensitive to delay, and often has large TCP congestion windows. However, the majority of the flows on the Internet today are from Web traffic, which is short-lived, more sensitive to delay, and typically has small TCP congestion windows. In particular, short-lived flows with small congestion windows frequently suffer from timeouts when encountering packet loss. AQM approaches to date fail to adequately protect short-lived flows, resulting in relatively low benefits from AQM techniques for more realistic traffic mixes of both long- and long-lived flows. This paper presents and evaluates a new AQM scheme, SHort-lived flow friendly RED (SHRED), targeted at providing better network performance for short-lived Web traffic. Using an edge hint to indicate the congestion window size in each packet provided by the flow source or by an edge router, SHRED preferentially drops packets from short-lived Web flows less often than packets from long-lived flows. We present a wide range of simulation results and analysis that demonstrate that SHRED protects short-lived flows from unnecessary timeouts, improving the response time characteristics for Web traffic when the router becomes congested, while not degrading overall network performance.

DOI

WPI-CS-TR-02-20

Share

 
COinS