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private network, it can only forward packets to the private network as they are requested.
DNS:
Domain Name System: A method to locate and translate Domain Names into Internet Protocol (IP)
addresses, where a Domain Name is a simple and meaningful name for an Internet address.
DSL:
Digital Subscriber Line: A technology that provides broadband connections over standard phone lines.
DSLAM:
Digital Subscriber Line Access Multiplexer: Using multiplexing techniques, a DSLAM receives
signals from customer DSL lines and places the signals on a high-speed backbone line. DSLAMs are
typically located at a telephone company’s CO (Central Office).
Encapsulation:
The inclusion of one data structure within another. For example, packets can be
encapsulated in an ATM frame during transfer.
FEC:
Forward Error Correction: An error correction technique in which a data packet is processed through an
algorithm that adds extra error correcting bits to the packet. If the transmitted message is received in error,
these bits are used to correct the errored bits without retransmission.
Firewall:
A firewall is a method of implementing common as well as user defined security policies in an effort
to keep intruders out. Firewalls work by analyzing and filtering out IP packets that violate a set of rules
defined by the firewall administrator. The firewall is located at the point of entry for the network. All data
inbound and outbound must pass through the firewall for inspection.
Fragmentation:
Breaking a packet up into smaller packets that is caused either by the transmission medium
being unable to support the original size of the packet or the receiving computer not being able to receive a
packet of that size. Fragmentation occurs when the sender’s MTU is larger than the receiver’s MRU.
FTP:
File Transfer Protocol. A standardized internet protocol which is the simplest way to transfer files from
one computer to another over the internet. FTP uses the Internet’s TCP/IP protocols to function.
Full Duplex:
Data transmission can be transmitted and received on the same signal medium and at the same
time. Full Duplex lines are bidirectional.
G.dmt:
Formally G.992.1, G.dmt is a form of ADSL that uses Discrete MultiTone (DMT) technology. G.dmt
incorporates a splitter in its design.
G.lite:
Formally G.992.2, G.lite is a standard way to install ADSL service. G.lite enables connections speeds
up to 1.5 Mbps downstream and 128 kbps upstream. G.lite does not need a splitter at the user end because
splitting is preformed at the remote end (telephone company).
Gateway:
A point on the network which is an entrance to another network. For example, a router is a
gateway that connects a LAN to a WAN.
Half Duplex:
Data transmission can be transmitted and received on the same signal medium, but not
simultaneously. Half Duplex lines are bidirectional.
HEC:
Headed Error Control: ATM error checking by using a CRC algorithm on the fifth octet in the ATM cell
header to generate a check character. Using HEC, either a single bit error in the header can be corrected or
multiple bit errors in the header can be detected.
HNP
: Home Network Processor
Host:
In context of Internet Protocol, a host computer is one that has full two way access to other computers
on the Internet.
