DSL modem

A digital subscriber line (DSL) modem is a device used to connect a computer or router to a telephone line which provides the digital subscriber line (DSL) service for connection to the Internet, which is often called DSL broadband. The modem connects to a single computer or router, through an Ethernet port, USB port, or is installed in a computer PCI slot. The more common DSL router is a standalone device that combines the function of a DSL modem and a router, and can connect multiple computers through multiple Ethernet ports or an integral wireless access point. Also called a residential gateway, a DSL router usually manages the connection and sharing of the DSL service in a home or small office network. Different DSL routers and modems support different DSL technology variants: VDSL, SDSL, and ADSL. A DSL router consists of a box with an RJ11 jack to connect to a standard subscriber telephone line. It has several RJ45 jacks for Ethernet cables to connect it to computers or printers, creating a local network. It usually also has a USB jack which can be used to connect to computers via a USB cable, to allow connection to computers without an Ethernet port. A wireless DSL router also has antennas to allow it to act as a wireless access point, so computers can connect to it forming a wireless network. Power is usually supplied by a cord from a wall wart transformer. It usually has a series of LED status lights which show the status of parts of the DSL communications link: Power light - indicates that the modem is turned on and has power Ethernet lights - there is usually a light over each Ethernet jack; a steady (or sometimes flashing) light indicates that the Ethernet link to that computer or device is functioning DSL light - a steady light indicates that the modem has established contact with the equipment in the local telephone exchange (DSLAM) so the DSL link over the telephone line is functioning; newer modems that support ADSL2+ bonding will have one light for each line Internet light - a steady light indicates that the IP address and DHCP protocol are initialized and working, so the system is connected to the Internet Wireless light - (only in wireless DSL modems) indicates that the wireless network is initialized and working Many routers provide an internal web page to the local network for device configuration and status reporting.