The Network layer
The Network layer handles connectivity of the APC Automatic Transfer Switch to the network, and includes packet traffic to and from the switch. Using the tests available in this layer, administrators can determine whether the network link to the target APC Automatic Transfer is available or not, the bandwidth availability, the rate of packet transmissions to and from the host and the uptime of the switch. In addition, the administrators can also determine the operational state of the network interfaces and the reason why any interface is down.
Figure 2 : The list of tests associated with Network layer
The Device Uptime and Network Interfaces tests have been discussed in the Cisco Router