Glossary

FXO

FXO (Foreign exchange office) - analog interface which uses a RJ-11 modular telephone cable to connect local calls to a PSTN central office or to PBX that does not support E&M signaling. This interface is used for off-premise extension applications.

FXS

FXS (Foreign eXchange Station) - analog interface which uses a standard RJ-11 modular telephone cable to connect directly to a standard telephone, fax machine, PBXs, or similar device, and supplies ring, voltage, and dial tone to the station.

IVR

IVR (Interactive voice response) - interactive voice system which communicates with user through voice prompts and menus. Wide used for voice mail systems, user authentification and authorization. The user activity usualy accepted through DTMF signals (using telephone keypad for example).

Internet telephony

Technology to get phone networks functionality using internet transport as carrier media. Brings connections with much less cost because of more rational use of channel bandwidth. The basic idea of internet telephony is a migration from channel to packet switching.

PBX

(P)BX ((Private) Branch Exchange) - the key component of modern telephony networks performing main call processing.

Softphone

Software tool implementing general phone functionality. Used widely in internet telephony networks. The main advantages of such tools is much less cost compared to hardware VOIP phones or gateways with easy upgrade availability.

Softswitch

Software implementing branch exchanges functionality for internet telephony networks. Grants carrier-class features such as automatic call routing based on route availability. Usualy used in conjunction with billing / monitoring systems to get AAA features.

Packet

Logicaly grouped block of data. Every packet has header (source/destination address and more) and payload part. Packets are used as main voice data carriers in internet telephony networks.