TCP Smart Framing: A Segmentation Algorithm to Improve TCP Performance

Abstract

In this paper we propose an enhancement to the TCP protocol, called TCP Smart Framing, or TCP-SF for short, that enables the Fast Retransmit/Recovery algorithm even when the congestion window is small. TCP-SF is particularly effective for short-lived flows, as most of the current Internet traffic is. Without modifying the TCP congestion control based on the additive-increase/ multiplicative-decrease paradigm, TCP-SF adopts a novel segmentation algorithm: while Classic TCP starts sending one segment, a TCP-SF source is allowed to send an initial window of 4 smaller segments, whose aggregate payload is equal to the connection’s MSS. This key idea can be implemented on top of any TCP flavor, from Tahoe to SACK, and requires modifications to the server behavior only.

Analytical results, simulation results, as well as testbed implementation measurements show that TCP-SF sources outperforms Classic TCP in terms of completion time.

This work was supported by the Italian Ministry for University and Scientific Research under the PlanetIP project and by the Center for Multimedia Radio Communications (CERCOM).