The context of this research is to analyze and model communication network using OPNET. The models are used to study how the performance of the network is affected by the different design decisions that are made to upgrade the network. And effect the different network configurations on different protocols. This research helps me to check the entire network, diagnosing device misconfigurations, errors, policy violations, and inefficiencies. To understand powerful modeling platform and also inherent understanding of topology and routing to detect network-level issues. The limitations of this study is strict to Ethernet Analyzing, TCP analyzing, OSPF Analyzing and queuing policies. Subjects included are: Communication network analyzing and modeling based on OPNET. Basic method of communication network analyzing Mechanism of network modeling System modeling of communication network OPNET modeling and analyzing Simulative experiment and analyzing of communication network modeling based on OPNET。