Figure 7 To analyze the reliability of the system in different topologies, 5 different scenarios have been used as follows: First Scenario: In this case, we do not use auxiliary central server IPC2 and network NCCS2. System network topology is as Figure 7. Second scenario: In this case, we do not use auxiliary central server IPC2 and network NCCS2 but communication path of IPC1 server also passes ESW1 switch, in addition to the switch ESW 2. This scenario network topology is presented in Figure 8. Figure 3: Architecture of SAS in Mianeh Aidoghmoush for the first loop.