Abstract— In this paper, we review the definition of avariant of TCP, called SmoothTCP, and describe one of itsversions which uses ICMP-SQ messages as its primarycontrol metric. This version of SmoothTCP is intended tobe used in environments subject to spurious errors, such asin wireless networks. We evaluate the behavior of thisversion of SmoothTCP by comparing it with the behavior ofStandard TCP in simulated environments with and withoutspurious errors. When there are no spurious errors,Standard TCP inherently drops packets and suffers largevariations in the congestion window size causing largevariations in round-trip time. In the case of spurious errors,Standard TCP encounters wide round-trip time variationsaround the retransmitted packet that was lost due to aspurious error. In both cases, SmoothTCP exhibits betterperformance with respect to round-trip time variation.

Index Terms—congestion control, RTT, spurious errors,TCP performance, SmoothTCP, wireless performance.

Cite: Elvis Vieira and Michael Bauer, "Round-trip Time Variation in SmoothTCP in the Face of Spurious Errors," Journal of Communications, vol. 1, no. 2, pp. 48-56, 2006.