Doro IP500PBXW, Руководство пользователя

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Administration Manual ip500pbxw – English
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D
Glossary
802.11
A family of specifications for wireless LANs developed by a working group of the IEEE. This in an
Ethernet protocol, often called Wi-Fi.
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 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 data rate, Ethernet.
ADSL
Asymmetric Digital Subscriber Line.
The most commonly deployed DSL for home users is asymmetrical DSL. 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.
analog
An analog signal is a signal that has had its frequency modified in some way, such as by amplifying
its strength or varying its frequency, in order to add information to the signal. The voice component
in DSL is an analog signal. See digital.
ATM
Asynchronous Transfer Mode
A standard for high-speed transmission of data, text, voice, and video, widely used within the
Internet. ATM data rates range from 45 Mbps to 2.5 Gbps. See data rate.
authenticate
To verify a 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 bit, IP address, network
mask.
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 systems 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.