The global Internet has experienced many years of sustained exponential growth doubling in size every nine months or faster [8]. Millions of users at tens of thousands of sites around the world depend on the global Internet as part of their daily work environment. This massive use of the Internet as well as the continuous interconnection of new groups arises many problems such as: packet loss, network congestion, insufficient bandwidth, increase in delay... In this thesis, we focus mainly on the problem of communication delay and bandwidth allocation. Our main goal is to find a way to minimize ...