For safer operation it is better to put CS on fixed IP address (of course in range like a PBX)
Follow the instructions:
page 18 to 21
SW 7 to ON, connect to CS (default AP address 192.168.2.101 ), change IP address, write to CS,power of, SW7 to 0, connect CS to network.
page 28 to 31
Register CS to PBX
Other SW is for diagnosis or site survey