ISDN Line Simulator User’s Manual
40-400-00012, Rev. E
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ETSI (European Telecommunications Standards Institute)
European Telecommunications Standards Institute. Formed in 1988 by the member
administrations of CEPT to broaden European Standards participation to include
manufacturers, research centers, private service providers, and user associations, as
well as Post and Telecommunications Administrations. ETSI has more than 250
members.
Hertz (Cycles Per Second)
A unit of frequency equal to one cycle per second and named for Heinrich Hertz, a
German mathematician.
I.331
I.331 is the ITU-T specification for the ISDN numbering plan. This is also known as
E.164.
I.430
The ITU-T Layer 1 specification for the ISDN BRI S/T interface, which consists of 4
wires. The S/T interface uses Alternate Space Inversion (ASI) line coding.
I.431
The ITU-T Layer specification for the Primary Rate Interface. See PRI, T-1 and E-1.
I.440
The ITU-T specification, commonly know as Q.920, which describes the general
network aspects of the LAP-D protocol (also known as DSS1).
I.441 (Q.921)
ISDN user-network interface - (D Channel) Layer 2 specification describing the
operational procedures of LAPD. Part of DSS1.
I.450
Also known as Q.930; the ITU-T specifications describing the general network
aspects of the ISDN D-Channel Layer 3 protocol.
I.451 (Please refer to Q.931 )
I.452
The ITU-T specifications for the 1988 specifications for the ISDN supplementary
services (Q.932). These services are now specified in Q.932 and Q. 957.
IEC (Interexchange Carrier)
A long distance company such as AT&T, MCI, Sprint, or hundreds of smaller
companies.
Inband Signaling
Controls Signals that travel on the same circuit and uses the same frequencies as the
call.
ISDN Address
The full address of an ISDN-capable device, consisting of the site’s ISDN numbering
plan and any additional terminal-specific digits signifying a particular user (NT2 and
TE1).