ADSL (Asymmetric Digital
Subscriber Line) - A term for one-way high speed
transmission of signals over plain single twisted-pair wiring
already run to residences. ADSL is provisioned with greater
downstream than upstream rates (hence asymmetric). These rates are
dependent on the distance of the user to the Central Office and can
vary from as high as 6 Mbps to as low as 128 Kbps.
Adapter Card -– An electronics board
installed in a PC, which provides a network interface to and from
that computer. Also called a network interface card (NIC).
Bandwidth - The amount of information or
data that can be sent over the Internet during a given period of
time. Bandwidth is usually stated in bits per second (bps), kilobits
per second (Kbps) or megabits per second (Mbps).
Bridge - A data communications device that
connects two or more networks and forwards packets between them and
function as routers. Bridges read and filter packets and frames.
Bridges do not require IP addresses and will pass broadcast traffic.
Broadband - A transmission medium or channel
that has a wider bandwidth than one voice channel (with a carrier
wave of a certain modulated frequency). It allows multiple services
like voice, data, video, etc. to transit over the network.
CO (Central Office) - A circuit switch that
terminates all the local access lines in a particular geographic
serving area; a physical building where the local telephone
company’s switching equipment is found. DSL lines running from a
subscriber’s home connect at their serving Central Office.
CPE (Customer Premise Equipment) –
Communications equipment that resides on the customer’s premises.
The CPE for DSL services is a DSL router or bridge.
Dedicated Line - – A transmission circuit
that is reserved by the provider for the full-time use of the
subsriber.
Downstream/Upstream - Downstream refers to
data flowing from the source such as an Internet service provider
(ISP) to the end user. Upstream refers to data flowing from the end
user back to the ISP.
Firewall - A firewall is a set of related
programs, located at a network gateway server, that protects the
resources of a private network from users from other networks. (The
term also implies the security policy that is used with the
programs.) An enterprise with an intranet that allows its workers
access to the wider Internet installs a firewall to prevent
outsiders from accessing its own private data resources and for
controlling what outside resources its own users have access to.
Kbps (Kilobits per second) - – A measure of
bandwidth capacity or transmission speed. The acronym stands for a
thousand bits per second.
Mbps (Million bits per second) -– A measure
of bandwidth capacity or transmission speed.
NAT - Network Address Translation - Provides
a pseudo-dynamic connection with the internet in a private IP space.
This is ideal for most instances where a static IP is not required.
If you want to read email, news, and browse the web at the highest
possible speeds and the lowest cost, then this is the choice for
you.
NIC (Network Interface Card) - The circuit
board or other form of computer hardware that serves as the
interface between a computer and the communications network.
Router - The device that connects multiple
computer networks by reading the address information on all data
packets. The packet information is read, and the packets are then
forwarded to the appropriate end station. Routers provide more
functionality than bridges, which simply connect dissimilar
networks.
SDSL (Symmetric Digital Subscriber Line) -–
Also called single line service, SDSL provides the same amount of
bandwidth in both directions.
Upstream - Refers to data flowing from the
end user back to the Internet service provider.
