Triz TZ6100i, User Manual

Page: 68 / 74

68
ISP (Internet Service Provider)
An organization offering and providing Internet services to the public and having its own
computer servers to provide the services offered.
Kbps (Kilobits per second or Thousands of bits per second)
A measure of digital transmission speed used in computer and telephone networks.
LAN (Local Area Network)
Last Mile
Refers to the local loop and is the difference between a local telephone company office
and the service user; a distance of about two to three miles.
LEC (Local Exchange Carrier)
One of the new U.S. telephone access and service providers that have grown up with
the recent U.S. deregulation of telecommunications.
LLC/ SNAP Encapsulation
Link Layer Control is a data encapsulation method used in PPP over ATM and on
Ethernet over ATM protocols to transport TCP/IP packets over ATM cells. . Each ISP
specifies which type of encapsulation it supports on its DSL service.
Loaded Pair
A twisted pair phone line with inductors, or loading coils, inserted periodically to flatten
the frequency response in the 4 KHz voiceband.
Loading Coil
A device used to extend the range of a local loop for voicegrade communications. They
are inductors added in series with the phone line which compensate for the parallel
capacitance of the line. They benefit the frequencies in the high end of the voice
spectrum at the expense of the frequencies above 3.6 KHz. Thus, loading coils prevent
DSL connections.
Local Loop
A generic term for the connection between the customer's premises (home, office,
whatever) and the provider's serving central office. Historically, this has been a wireline
connection; however, wireless options are increasingly available for local loop capacity.
Also colloquially referred to as "the last mile" (even though the actual distance can
vary).
Low Pass Filter
A signal filter installed in a customer premises DSL modem (ATUR), which would not
modify the low frequencies present in its input signal (the POTS transmission is sent
unmodified to a phone), but would prevent the high-frequency components (data) from
reaching a customer's telephone.