Research on TCP throughput model is an important aspect of research on network protocols.Compared with some other models

the model given by Padhye is more accurate to describe the relation between TCP throughput and round trip time

rate of packet loss

and time out limit.But under heavy network load

Padhye model doesn't match the results very well.In this paper

the performance of TCP under heavy network load is analyzed

and a Padhye Model based TCP throughput model in heavy network load is given forth.The experiment indicates that this model matches the results better than Padhye model in heavy network load.