Alarm Indication Signal. A signalling condition of all "1"'s on a Primary Rate interface, indicating that the PRI equipment has failed.
ASCII
American Standard Code for Information Interchange.
B
BTNR
British Telecommunications Network Requirement.
C
CELP
Code Excited Linear Prediction.
CLC
Calling/Called Line Category.
CLI
Calling Line Identifier.
Codec
Coder Decoder.
D
DASS2
Digital Access Signalling System Number 2. The current version of the DASS protocol. Often just referred to as DASS.
DiffServ
Differentiated Services.
DPNSS
Digital Private Network Signalling System.
DTMF
Dual tone multifrequency.
E
ECP
Encryption Control Protocol.
Ethernet
Baseband LAN specification invented by Xerox Corporation and developed jointly by Xerox, Intel, and Digital Equipment Corporation.
ETSI
European Telecommunications Standards Institute.
F
Fast Start
Part of the H.248 / H.323 standards. Fast Start reduces voice path connection delay during call setup.
G
G.711
Describes the 64 Kbit/s PCM voice coding technique. In G.711, encoded voice is already in the correct format for digital voice delivery in the PSTN or through PBXs. This is described in the ITU-T G-series recommendations.
G.723
Describes a compression technique that can be used for compressing speech or audio signal components at a very low bit rate as part of the H.324 family of standards.
G.729a
Describes CELP compression where voice is coded into 8 Kbit/s streams. There are two variations of this standard (G.729 and G.729 Annex A) that differ mainly in computational complexity; both provide speech quality similar to 32Kbit/s ADPCM and are described in the ITU-T standard in its G-series recommendations.
H
H.225
An ITU standard that governs H.225.0 session establishment and packetisation. H.225.0 actually describes several different protocols: RAS, use of Q.931 and use of RTP.
H.245
An ITU standard that governs H.245 endpoint control.
H.323
Extension of ITU-T standard H.320 that enables videoconferencing over LANs and other packet-switched networks, as well as video over the Internet.
H.450
An ITU standard that defines supplementary services.
Hz
Hertz.
I
IP
Internet Protocol.
ISDN
Integrated Services Digital Network.
ITU
International Telecommunication Union.
ITU-T
Telecommunication standardization sector of ITU.
L
LAN
Local Area Network.
LED
Light Emitting Diode.
M
MCU
Multipoint Control Unit.
MIB
Management Information Base.
N
NFAS
Non-Facility Associated Signalling.
NMS
Network Management System.
NTP
Network Time Protocol.
NVRAM
Non-Volatile Random Access Memory.
O
OLI
Originating Line Indicator (ITU-T/CCS #7).
P
PAP
Password Authentication Protocol.
PAMS
Perceptual Analysis Measurement System.
PHB
Per-Hop Behaviour.
PBX
Private Branch Exchange.
PC
Personal Computer.
POST
Power On Self Test.
Prepend
Add to the start of.
PRI
Primary Rate Interface.
PSQM
Perceptual Speech Quality Measurement.
PSTN
Public Switched Telephone Network.
Q
Q.931
ITU-T specification for signalling to establish, maintain, and clear ISDN network connections.
QSIG
A signalling standard. Common channel signalling protocol based on ISDN Q.931 standards and used by many digital PBXs. Q (point of the ISDN model) Signalling.
QOS
Quality of Service.
R
RADIUS
Remote Authentication Dial In User Service (RFC 2865).
RAI
Remote Alarm Indication. An indication in the channel framing information on a Primary Rate Interface showing that the equipment signalling the condition detects a problem in the link or attached equipment.
RAS
Registration Admission and Status.
RS-232
Recommended Standard 232 (computer serial interface, IEEE).
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