TCP/IP modeling and validation

We discuss in this article the different issues to be considered when model ing the TCP protocol in a real environment. The discussion is based on meas urements we made over the Internet. We show that the Internet is so heterog eneous that a simplistic assumption about TCP congestion control or the net work may lead to erroneous results. We outline some of our results in this field, and we present a novel approach for a correct validation of a model for TCP.