AN APPROXIMATE GSPN MODEL FOR THE ACCURATE PERFORMANCE ANALYSIS OF CORRELATED TCP CONNECTIONS

摘要

A number of analytical models of the TCP behavior have been presented in the recent literature; most of them consider the interaction among TCP connections sharing one bottleneck link, but assume that these connections behave independently of each other. In this paper we develop a new model to describe the behavior of a number of TCP connections that share a bottleneck link, considering the effects of the synchronization among connections. The model is based on Markovian assumptions and on two GSPN (Generalized Stochastic Petri Net) descriptions of the system. From the two GSPN descriptions, using a fixed point algorithm, several interesting performance metrics referring to TCP connections can be derived. A validation of our modeling approach is provided through extensive comparisons of the model's results with the output of the LBL simulator, "ns version 2". Comparisons show that our model succeeds in providing an accurate representation of the behavior of TCP connections under several different settings.