WPI - Computer Science Department, MS Thesis Presentation Maryam Ataei Kachooei " Improving TCP Slow Start Performance in Wireless Networks with SEARCH

Maryam Ataei Kachooei

PhD 90 Student

WPI – Computer Science Department

Monday, December 16, 2024

Time: 12:00 PM – 1:00 PM 

Zoom link: https://wpi.zoom.us/j/3828380151

 Advisor: Prof. Mark Claypool

Reader: Prof. Shubbhi Taneja

Abstract:

 Transmission Control Protocol slow start is designed to gradually ramp up the congestion window, aiming to match the available network capacity while minimizing congestion. However, this mechanism often struggles in high bandwidth-delay product networks, leading to premature exits from slow start or excessive packet loss.

 This thesis introduces a novel algorithm, Slow start Exit At Right CHokepoint (SEARCH), which aims to address these challenges by accurately determining the point at which slow start should exit, based on the analysis of delivered bytes compared to expected rates over multiple round-trip times. By smoothing delivery rates over several round-trip times and normalizing bandwidth estimates, SEARCH adapts to varying conditions, preventing early exits while maintaining high throughput without causing unnecessary congestion. 

The thesis details the design and implementation of SEARCH across multiple high bandwidth-delay product network types, including satellite (GEO, LEO), and 4G LTE networks, compared to traditional TCP (CUBIC without HyStart) and default TCP (CUBIC with HyStart). Extensive experiments show that SEARCH consistently exits slow start at the right capacity point, improving throughput and reducing packet loss across diverse network environments.