The enterprise class model of switched LAN in the form of a colored Petri net is represented. The components of the model are submodels of switch, server and workstation. For the evaluation of network response time a special measuring workstation model is proposed. It counts response times for each request and calculates the average response time. For the simulation of network behavior and accumulation of statistical information, CPN Tools was applied. Hierarchical nets usage allows the convenient representation of an arbitrary given structure of LAN. The influence of such features as limitations of switch's buffer size and dynamic maintenance of switching table were estimated.