Reducing Flow-Completion Time for Small Flows by Modifying

Slow-Start

Affan Rauf (05030063)

Problem

Slow start stretches a small over several RTTs even if they are capable to complete in few

About 70% of the gateway traffic consists of Web transfers

About 85% of the packets are transferred by the server while flows are still in their slow start phase

Recent Suggestions

RFC 3390

TCP’s initial window increased to 2-4 segments

Network Adaptive TCP Slow Start

(closest to the idea I had in mind)

Uses past history from other connections and the file size

My Hypothesis

Why can’t we can guess if the congestion is decreasing based upon a few recent round trip delays

Being optimistic we can increase the window size e.g. by extrapolation

Issues

How much to increase congestion window without adding to the congestion?

Is linear interpolation and the gradient of the line a good estimate?

Can we scale it for longer flows?

Line of Action

Comparison with RFC 3390’s results

(based on Flow-completion time)Effect on throughput in the presence of

AQM techniques.

If you found that useless, please tell me NOW!

Questions?