Telos Zephyr Xstream - Manual (Page 367)

USER’S MANUAL
Appendix 10 – Glossary 355
Line Format, T1 Modern T1 circuits usually use either Superframe (sometimes called SF or D4)
or Extended Superframe (sometimes called ESF) line formatting. The type of framing used is
determined by your Telco. ESF is preferred. See ESF and SF
Line Side This is the side of a central office switch that the subscriber's telephone lines are
connected to. The main reason for distinguishing between this and the trunk side is that certain
customer related features (Such as CLASS and Centrex features) are inapplicable to trunks. See
also Trunk Side. 2) The user side of a PBX. Also called the station side.
Line Termination See LT.
Livewire TM This is the trade name used by Axia Audio (a division of Telos‐Systems) to describe
the audio streams utilized in their networked audio system.
Local Access and Transport Area See LATA.
Local Exchange Carrier See LEC and CLEC.
Long Distance If your local Telco is a former Bell Operating Company then any call outside of
your LATA or any Interstate call is considered long distance and is handled by an IEC. The above
is true regardless of whether you are referring to a dedicated line or a dial up call. 2) However,
under the current state of deregulation, toll calls within a LATA may now be covered by the IEC,
and in some cases RBOCs are being permitted to handle InterLATA calls.
Loop The telephone circuit from the CO to the customer’s premises. Generally refers to a
copper cable circuit.
Loop Current Disconnect Supervision Another name for CPC. See CPC
Loop Qualification Process of actually measuring the loss on a prospective ISDN line to see if it
can be used for ISDN service. The actual loss on the line (usually measured at 40 kHz) is the
determining factor whether ISDN service can be offered without a repeater. Generally ISDN is
available up to 18,000 feet from the serving Central Office. It may not be available within this
range, or may be available further from the CO. Only a loop qualification can tell for sure. Not all
Telcos will extend ISDN lines with repeaters.
Loop Start Line A plain old telephone line. The telephone terminal signals the “off hook”
condition by allowing DC current to flow. See Ground Start Trunk. See also Glare.
Loop Start Trunk A plain old telephone line connected to a PBX switch. See Loop Start Line. The
PBX signals the “off hook” condition by allowing DC current to flow. Ground Start Trunks are
generally preferred for use on PBXs to prevent glare. See Ground Start Trunk. See also Glare.
The Telco may call this a “Loop Start Line”.
LOS Loss Of Signal. An LED or other indicator that illuminates if a signal is absent. This
terminology is commonly used with T‐ 1 equipment.
LT ‐ Line Termination The electrical and protocol specifications for the Central Office end of an
ISDN line. If you wish to connect an ISDN terminal (such as a Zephyr Xstream) to a PBX the PBX
must support LT ISDN. See also NT and Line Card
Lucent Technologies Company which now makes the former AT&T 5ESS switch, as well as
various other piece of Telco gear and semiconductors. Lucent was split off from AT&T in 1996
and owns Bell Labs. As of approximately 1999 Lucent sold their telephone set manufacturing