Communication Using a Reconfigurable and Reliable Transport Layer Protocol

摘要

Although TCP is known to be inefficient over networks such as wireless, satellite, and log-fat-pipes, it is still the most widely used transport layer protocol even on these networks. In this paper, we explore an alternative strategy for designing a reliable transport layer protocol that is much more suitable for today's mobile and other types of non-conventional networks. The objective here is to have a single protocol that is compatible with today's communication software and can be easily made to perform better over all types of network. The outcome of the research is a reconfigurable, user-level, reliable transport layer protocol, called RRTP (Reliable and Reconfigurable Transport Protocol) that is TCP-friendly, i.e. it asymptotically converges to fairness as in the case of LIMD (Linear Increase Multiplicative Decrease) algorithms. The protocol is implemented on top of UDP, but it can also easily be incorporated into OS kernels. The paper presents the RRTP algorithm and the key parameters that are necessary for its reconfiguration. We evaluate our protocol using the standard network simulation tool (ns2). Several representative network configurations are used to benchmark the performance of our protocol against TCP in terms of network throughput and congestion loss rate. It is observed that under normal operating conditions, our protocol has a performance advantage of 30% to 700% over TCP in lossy, wireless environments as well as high bandwidth, high latency networks.