ATL Telecom AM30 - Manual (Page 168)

168 ATL Telecom User Guide
AM30
domain name A domain name is a user-friendly name used in place of its associated IP
address. For example, www.globespan.net is the domain name associated with IP address
209.191.4.240. 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, e.g., http://www.globespan.net/index.html. See
also 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.
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.
filtering
To screen out selected types of data, based on filtering rules. Filtering can be
applied in one direction (upstream or downstream), or in both directions.
filtering rule
A rule that specifies what kinds of data the a routing device will accept and/or
reject. Filtering rules are defined to operate on an interface (or multiple interfaces) and in a
particular direction (upstream, downstream, or both).
firewall Any method of protecting a computer or LAN connected to the Internet from intrusion or
attack from the outside. Some firewall protection can be provided by packet filtering and Network
Address Translation services.
FTP
File Transfer Protocol
A program used to transfer files between computers connected to the Internet. Common uses
include uploading new or updated files to a web server, and downloading files from a web server.
GGP
Gateway to Gateway Protocol. An Internet protocol that specifies how gateway routers
communicate with each other.
Gbps
Abbreviation for Gigabits (“GIG-uh-bits”) per second, or one billion bits per second.
Internet data rates are often expressed in Gbps.
hop
When you send data through the Internet, it is sent first from your computer to a router,
and then from one router to another until it finally reaches a router that is directly connected to the
recipient. Each individual “leg” of the data’s journey is called a hop.
hop count
The number of hops that data has taken on its route to its destination.
Alternatively, the maximum number of hops that a packet is allowed to take before being
discarded (see also TTL).
host
A device (usually a computer) connected to a network.
HTTP Hyper-Text Transfer Protocol
HTTP is the main protocol used to transfer data from web sites so that it can be displayed by web
browsers. See also web browser, web site.
ICMP
Internet Control Message Protocol
An Internet protocol used to report errors and other network-related information. The ping
command makes use of ICMP.
IGMP
Internet Group Management Protocol
An Internet protocol that enables a computer to share information about its membership in
multicast groups with adjacent routers. A multicast group of computers is one whose members
have designated as interested in receiving specific content from the others. Multicasting to an
IGMP group can be used to simultaneously update the address books of a group of mobile
computer users or to send company newsletters to a distribution list.
in-line filter
See microfilter.
Internet The global collection of interconnected networks used for both private and
business communications.
intranet
A private, company-internal network that looks like part of the Internet (users
access information using web browsers), but is accessible only by employees.
IP
See TCP/IP.
IP address Internet Protocol address
The address of a host (computer) on the Internet, consisting of four numbers, each from 0 to 255,