Cisco ATA 190 Administration Manual page 69

Foreign Exchange Office. An FXO interface connects to the public switched phone network (PSTN)
FXO
central office and is the interface offered on a standard phone. Cisco FXO interface is an RJ-11
connector that allows an analog connection at the PSTN central office or to a station interface on a
PBX.
Foreign Exchange Station. An FXS interface connects directly to a standard phone and supplies ring,
FXS
voltage, and dial tone. Cisco's FXS interface is an RJ-11 connector that allows connections to basic
phone service equipment, keysets, and PBXs.
G
Describes the 64-kbps PCM voice coding technique. In G.711, encoded voice is already in the correct
G.711
format for digital voice delivery in the PSTN or through PBXs. Described in the ITU-T standard in its
G-series recommendations.
Describes a compression technique that can be used for compressing speech or audio signal
G.723.1
components at a very low bit rate as part of the H.324 family of standards. This Codec has two bit
rates associated with it: 5.3 and 6.3 kbps. The higher bit rate is based on ML-MLQ technology and
provides a somewhat higher quality of sound. The lower bit rate is based on CELP and provides
system designers with more flexibility. Described in the ITU-T standard in its G-series
recommendations.
Describes CELP compression where voice is coded into 8-kbps streams. There are two variations of
G.729A
this standard (G.729 and G.729 Annex A) that differ mainly in computational complexity; both
provide speech quality similar to 32-kbps ADPCM. Described in the ITU-T standard in its G-series
recommendations.
A gateway allows SIP or H.323 terminals to communicate with terminals configured to other protocols
gateway
by converting protocols. A gateway is the point where a circuit-switched call is encoded and
repackaged into IP packets.
H
H.323 allows dissimilar communication devices to communicate with each other by using a standard
H.323
communication protocol. H.323 defines a common set of CODECs, call setup and negotiating
procedures, and basic data transport methods.
I
Internet Control Message Protocol
ICMP
OL-31821-02
Cisco ATA 190 Analog Telephone Adapter Administration Guide for SIP (Version 1.1)
Glossary
GL-3