We analyze two alternative retransmission timers for the Transmission Control Protocol (TCP). We first study the retransmission timer of TCP-Lite which is considered to be the current de facto standard for TCP implementations. After revealing four major problems of TCP-Lite's retransmission timer, we propose a new timer, named the
Eifel retransmission timer
, that eliminates these. The strength of our work lies in its hybrid analysis methodology. We develop models of both retransmission timers for the class of network-limited TCP bulk data transfers in steady state. Using those models, we predict the problems of TCP-Lite's retransmission timer and develop the Eifel retransmission timer. We then validate our model-based analysis through measurements in a real network that yield the same results.
Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
I Im mp pr ro ov vi in ng g t th he e E Ef ff fi ic ci ie en nc cy y o of f t th he e O OS SI I C Ch he ec ck ks su um m C Ca al lc cu ul la at ti io on n. .
Keith Sklower
Computer Systems Research GroupComputer Science Division Department of Electrical Engineering and Computer Sciences University of California Berkeley, California 94720 ABSTRACT It is known that using larger byte-sizes to access memory usually results in faster computations of checksum algorithms. This paper proposes two different ways to use larger byte-sizes to improve the performance of the OSI checksum. First, an algorithm is presented that computes the 8−bit checksum using 16−bit integers. It is shown that this algorithm yields a 5 to 20 percent performance improvement on many architectures. Second, the benefits of expanding the basic computation unit of the OSI checksum algorithm to 16−bits integers is considered. This change can yield an additional performance improvement of up to 50% and greatly extended error detection properties, although it is incompatible with the current standard. The measurements of these algorithms are compared with some taken of checksums in common use, such as IP and XNS †.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.