An ADSL modem, also known as a DSL modem, is a device used to connect one or more computers to a phone line, in order to use an ADSL service. To the end-user, it is functionally very similar to an analogue modem, however the underlying technology is substantially different. Some ADSL modems also manage the connection and sharing of the ADSL service with a group of machines, making an ADSL router or ADSL modem/router a more accurate name for the device.

Features

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Apart from connecting to an ADSL service, many modems offer additional integrated features:

• ADSL2 or ADSL2+ support
• Router functionality that uses NAT to share the connection
• An 802.11b or 802.11g wireless access point
• A built-in switch (typically 4 or 5 ports)
• VPN termination
• DHCP server
• Dynamic DNS client
• VoIP functionality including QoS

Many ADSL modems can have their firmware upgraded to support additional features or fix existing problems. This can be done over the network, or using a dedicated serial connection.

Manufacturers

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• Alcatel
• AVM
• Belkin
• Billion (company)
• D-Link
• Draytek
• Efficient Networks
• Huawei
• Netgear
• Netopia
• Sagem
• Thomson
• Westell
• 2Wire
• U.S.Robotics

Networking hardware

Router ADSL