 Like mobile phones, mobile broadband modems can be SIM locked to a particular network provider.Unlocking a modem is achieved the same way as unlocking a phone, by using an 'unlock code'.Some devices referred to as "broadband modems" are residential gateways, integrating the functions of a modem, router typically employing network address translation (NAT), Ethernet switch, WiFi access point, DHCP server, firewall, among others.