Optimization of TCP SACK

Type :

Term papers

Pages :

4 pages

Format :

.pdf

Published date :

06/08/2009

Category :

Science & technology

Sub category :

Computer science

Oboulo.com selection criteria

$ 6.95 Add to cart

Summary :

Introduction
The Transport Control Protocol - TCP
TCP implementations
TCP sack performance issues
Conclusions
Bibliography

Abstract

Internet is expanding rapidly over entire glob with heterogeneous networks. tcp/IP protocol suite is an inseparable part of Internet. Hence, the efficiency of the protocols is plays a vital role in performance of Internet. The increasing use of wireless links in expanding Internet has brought out some serious performance issues of tcp, which was originally designed and deployed over a wired network. Wired links are less prone to channel errors. Due to inherent problem of tcp, it fails to differentiate losses by actual reason, so they are not treated fairly. Therefore, performance is often compromised by unnecessary congestion window, cwnd reductions and RTOs. Basic tcp has gone through a number of revisions in order to improve performance. Among all of them, sack tcp is considered to be the most efficient scheme because of its ability to avoid unnecessary retransmissions based on sack information. sack tcp also fails to discriminate the cause of the loss: congestion or corruption. If random losses can be categorized apart from losses due to severe congestion, then irrational decision of 'cwnd' reduction can be avoided. This will surely lead to performance improvement due to effective bandwidth utilization and consistent flow in random packet losses. In this paper, sack tcp is modified to delay fast recovery after one packet loss, until subsequent loss in the same windows is encountered. Keywords: tcp sack, cwnd, Congestion, Corruption, Fast Recovery