Abstract: This paper puts forward the theory that OPNET can be used to make simulated analysis on the scheme of network expansion and upgrading aiming at the unpredictability of the effect of enterprise network when it is expanded and upgraded, and then estimates the feasibility of the scheme of network expansion and upgrading by analyzing the change of the key performance parameters before and after expansion and upgrade of the network. Practice shows that using OPNET to make a simulated analysis on the scheme of network expansion and upgrading can not only lower the risk of network expansion and upgrading greatly, but also verify the feasibility of the scheme of network expansion and upgrading efficiently.

Key words: enterprise network, scheme of expansion and upgrading, OPNET, simulated analysis