In this paper authors present simulation model of an alloptical network, consisting of dual 4 × 4 switches. The analytical model of the considered all-optical network is a two-phase queuing system with a limitation on the shared buffer size. Authors have provided numerical results of system states probabilities including packet loss probability in transient mode, depending on the ratio of service and arrival rates, and also transient time. A comparison of analytical and simulation modeling is also carried out.