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Internet Security Router User
’s Manual
Appendix 16. Glossary
143
16 Glossary
10BASE-T
A designation for the type of wiring used by Ethernet networks with a data rate of 10
Mbps. Also known as Category 3 (CAT 3) wiring. See also data rate, Ethernet.
100BASE-T
A designation for the type of wiring used by Ethernet networks with a data rate of 100
Mbps. Also known as Category 5 (CAT 5) wiring. See also data rate, Ethernet.
ADSL
Asymmetric Digital Subscriber Line
The most commonly deployed "flavor" of DSL for home users. The term asymmetrical
refers to its unequal data rates for downloading and uploading (the download rate is
higher than the upload rate). The asymmetrical rates benefit home users because they
typically download much more data from the Internet than they upload.
authenticate
To verify user
’s identity, such as by prompting for a password.
binary
The "base two" system of numbers, that uses only two digits, 0 and 1, to represent all
numbers. In binary, the number 1 is written as 1, 2 as 10, 3 as 11, 4 as 100, etc.
Although expressed as decimal numbers for convenience, IP addresses in actual use
are binary numbers; e.g., the IP address 209.191.4.240 is
11010001.10111111.00000100.11110000 in binary. See also bit, IP address, network
mask.
bit
Short for "binary digit," a bit is a number that can have two values, 0 or 1. See also
binary.
bps
bits per second
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
Internet Security Router'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.
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. 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 also
domain name.
domain name
A domain name is a user-friendly name used in place of its associated IP address. For
example, www.hinet.net is the domain name associated with IP address 168.95.1.88.
Domain names must be unique; their assignment is controlled by the Internet
Corporation for Assigned Names and Numbers (ICANN). Domain names are a key