Hx1-Hx2 Manual-1.4.1 - Telos

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ILEC – Incumbent Local Exchange Carrier. A local Exchange Carrier which entered the
marketplace before the enactment of the 1996 Telecom act;. i.e. a telephone company which is
neither an Indi nor an RBOC. See LEC and CLEC.
IMUX – See Inverse Multiplexing.
In Band Signaling- A signaling system where network information such as address and routing
information are handled over the communications (voice) path itself. Usually the information is
represented in the form of audible tones, however DC loop current signaling also qualifies as In
Band Signaling. See also CCIS.
Incumbent Local Exchange Carrier. See ILEC. See also CLEC & LEC
Independent – Any of the phone companies in existence at the time of divestiture that were not
affiliated with the Bell System. See RBOC, LEC, and CLEC.
Indi- See Independent.
Interconnect Company- A vendor of telecommunications CPE other than a BOC or AT&T.
This term was originated by AT&T and was meant to be derisive towards the fledgling industry
when the courts said it was OK for end users to buy equipment from someone other than the
Bell System. This industry flourished, in spite of AT&T’s disdain, and ironically, the RBOCs
were not allowed to sell CPE under the terms of the break up of AT&T. With the current state
of deregulation, the RBOCs are slowly re-entering this business. The term is now considered
archaic at the time of this writing.
Inter-exchange Carrier- See IEC.
Interwork- The ability of two different type of networks to communicate seamlessly. For
example, ISDN can interwork calls to both the POTS network and the Switched-56 network.
ISDN - Integrated Services Digital Network- A relatively new and highly flexible type of
telephone service which allows dialing on digital channels with multiple bi-directional “Bearer”
channels each with a capacity of 56 or 64 Kbps and a single bi-directional “D channel”. See BRI
and PRI.
ISDN Protocol - The “language” used for communication between the Telco’s switch and the
customer’s Terminal Adapter. Each ISDN circuit has one protocol, and the protocol has no
effect on where or whom one may call. See ETS 300, National ISDN, and Custom ISDN.
ISDN 2- A term used in Europe for ISDN BRI. Also called SØ. Not to be confused with
National ISDN-2. See BRI.
ISDN 30- A term used in Europe for ISDN PRI. Also called S2M. See PRI.
ISG – Incoming Service Grouping. A Hunt Group. See Hunt Group.
IXC- IntereXchange Carrier- See IEC.
Kbps- KiloBits Per Second. Measure of digital channel capacity.
Key Telephone System – A system that allows multiple telephones to share multiple predetermined
telephone lines. The system provides indicators to allow the user’s to understand
the status of each line available on a given phone. In its most basic form it is up to the user to
provide the intelligence to select an unused line, or answer a ringing line, for example. See also
PBX.
LATA- Local Access and Transport Area. The area within which calls are routed by your Local
Exchange Carrier (LEC). Under the divestiture of the Bell System calls going outside of this
area must be handled by an Interexchange carrier (IEC). With the latest round of de-regulation
the usual IEC companies are being allowed to compete in the IntraLATA long distance market