Design of TCP Protocol with Low Priority for Improving TCP Performance

Service prioritization among different traffic classes is an important goal for the Internet. In this paper, we devise a new distributed algorithm to realize a low-priority service from the network endpoints. To this end, we develop TCP Low Priority(TCP-LP), a distributed algorithm whose goal is to utilize only the excess network bandwidth. the key mechanisms unique to TCP-LP congestion control are the use of one-way packet delays for early congestion indications and a TCP transparent congestion avoidance policy. the simulation results show that 1) Multiple TCP-LP flows share excess bandwidth fairly; 2) Substantial amounts of excess bandwidth are available to the low-priority class, even in the presence of “greedy” TCP flows; 3) Despite their low-priority nature, TCP-LP flows are able to utilize significant amounts of available bandwidth in a wide-area network environment.