A cellular modem sends traffic from one point to the other. This is different from a router that can segment traffic based on rules. Modems do not provide data protection or a firewall function. The connectivity to and from a modem is limited to one type of connection. They do not come with extra ethernet, WiFi, Bluetooth or other connections. To achieve these functions, you need a router or gateway. Modems are perfect for applications where additional functionality is handled by another device.