FXO

FXS

Glossary

Foreign Exchange Office. An FXO interface connects to the public switched telephone network (PSTN) central office and is the interface offered on a standard telephone. 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 telephone and supplies ring, voltage, and dial tone. Cisco's FXS interface is an RJ-11 connector that allows connections to basic telephone service equipment, keysets, and PBXs.

G

G.711

Describes the 64-kbps 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. Described in the ITU-T standard in its

 

G-series recommendations.

G.723.1

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. 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 additional flexibility. Described in the ITU-T standard in its G-series

 

recommendations.

G.729A

Describes CELP compression where voice is coded into 8-kbps 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 32-kbps ADPCM. Described in the ITU-T standard in its G-series

 

recommendations.

gateway

A gateway allows SIP or H.323 terminals to communicate with terminals configured to other protocols

 

by converting protocols. A gateway is the point where a circuit-switched call is encoded and

 

repackaged into IP packets.

H

H.245

An ITU standard that governs H.245 endpoint control.

H.323

H.323 allows dissimilar communication devices to communicate with each other by using a standard

 

communication protocol. H.323 defines a common set of CODECs, call setup and negotiating

 

procedures, and basic data transport methods.

I

ICMP

Internet Control Message Protocol

Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (SIP)

 

OL-3410-01

GL-3

 

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Cisco Systems ATA186I2ARF manual GL-3