The Linksys CIT400 is a cordless phone system that also acts as a wireless router. It features DECT 1.9 GHz technology for clear and secure calls, a 2.2-inch color display, and a built-in speakerphone. The router portion allows for wireless connectivity with speeds of up to 54 Mbps and has WEP, WPA, and WPA2 security protocols. It also includes a built-in answering machine with up to 20 minutes of recording time. The CIT400 supports up to four handsets and can be expanded up to a total of six.

The CIT400 is a router manufactured by the company Linksys that allows multiple devices to connect to a network and communicate with each other. It works by receiving data packets from devices and forwarding them to their intended destination. The router is assigned a unique IP address 192.168.15.1, which serves as its identifier on the network.

To access the router's settings and configure its functions, users can log in using a web browser and their admin and admin. Once logged in, users can customize various settings such as network name, password, and security protocols. They can also set up parental controls, prioritize bandwidth usage, and monitor network activity.