User's Manual

66xx/67xx Router Users Guide 176
Broadband A telecommunications technology that can send different types of data
over the same medium. DSL is a broadband technology.
Broadcast To send data to all computers on a network.
DHCP Dynamic Host Configuration Protocol
DHCP automates address assignment and management. When a
computer connects to the LAN, DHCP assigns it an IP address from a
shared pool of IP addresses; after a specified time limit, DHCP returns the
address to the pool.
DHCP relay Dynamic Host Configuration Protocol relay
A DHCP relay is a computer that forwards DHCP data between
computers that request IP addresses and the DHCP server that assigns
the addresses. Each of the device’s interfaces can be configured as a
DHCP relay. See DHCP.
DHCP server Dynamic Host Configuration Protocol server
A DHCP server is a computer that is responsible for assigning IP
addresses to the computers on a LAN. See DHCP.
Digital Of data, having a form based on discrete values expressed as binary
numbers (0’s and 1’s). The data component in DSL is a digital signal. See
analog.
DNS Domain Name System
The DNS maps domain names into IP addresses. DNS information is
distributed hierarchically throughout the Internet among computers called
DNS servers. For example, www.yahoo.com is the domain name
associated with IP address 216.115.108.243. When you start to access a
web site, a DNS server looks up the requested domain name to find its
corresponding IP address. If the DNS server cannot find the IP address, it
communicates with higher-level DNS servers to determine the IP address.
See domain name.
Domain name A domain name is a user-friendly name used in place of its associated IP
address. Domain names must be unique; their assignment is controlled by
the Internet Corporation for Assigned Names and Numbers (ICANN).
Domain names are a key element of URLs, which identify a specific file at
a web site. See DNS.
Download To transfer data in the downstream direction, i.e., from the Internet to the
user.
DSL Digital Subscriber Line
A technology that allows both digital data and analog voice signals to
travel over existing copper telephone lines.
Encryption keys See network keys
Ethernet The most commonly installed computer network technology, usually using
twisted pair wiring. Ethernet data rates are 10 Mbps and 100 Mbps. See
also 10BASE-T, 100BASE-T, twisted pair.
Firewall A firewall is protection between the Internet and your local network. It acts
as the firewall in your car does, protecting the interior of the car from the
engine. Your car's firewall has very small opening that allow desired
connections from the engine into the cabin (gas pedal connection, etc),