Glossary

CPL

See Call Processing Language.

Call Processing Language

An XML application to define rules for call processing (e.g. to route all calls to a cell phone during lunchtime). Decisions can be made upon the calling party number or the called party number, date or time - just to name a few, while actions usually include rejection or redirections of calls.

Extensible Markup Language

A standard methodology with formal syntax for adding information to a document relating to its structure and/or content by applying identifiers for elements of information in a neutral way, stored in a neutral form, independent of systems, devices and applications.

Gatekeeper

In the H.323 world, the gatekeeper provides several important functions. First, it controls access to the network, allowing or denying calls and controlling the bandwidth of a call. Second, it helps with address resolution, making possible email type names for end users, and converting those into the appropriate network addresses. Also handles call tracking and billing, and call signaling.

GK

See Gatekeeper.

Gateway

A gateway is a communication instance that translates (call) data between different networks (e.g. IP and PSTN) or protocols. A signaling gateway translates between two or more signaling protocols (like H.323 or SIP), while a media gateway usually performs transcoding of media streams (e.g. G.711 to GSM).
Of course a gateway may as well combine all functionality described above.

GW

See Gateway.

H.323

ITU standard for videoconferencing over packet switched networks such as Internet.

H.323

See H.323.

Media Gateway Control Protocol

A protocol for IP telephony that enables a caller with a PSTN phone number to locate the destination device and establish a session.

MGCP

See Media Gateway Control Protocol.

PBX

See Private Branch eXchange.

PSTN

See Public Switched Telephone Network.

Private Branch eXchange

A device used by organisations to allow a single access number to offer multiple lines to outside callers, and to allow internal staff to share a range of external lines.

Public Switched Telephone Network

The worldwide voice telephone network.

QoS

See Quality of Service.

Quality of Service

Measure of performance for a transmission system that reflects its transmission quality and service availability.

Real Time Protocol

RTP is designed to provide end-to-end network transport functions for applications transmitting real-time data, such as audio, video, or simulation data, over multicast or unicast network services.

RTP

See Real Time Protocol.

SIP

See Session Initiation Protocol.

Session Initiation Protocol

IETF standard for session initiation in multi-purpose communication systems.

Voice over IP

The transmission of voice over data networks that uses the Internet Protocol (IP).

VoIP

See Voice over IP.

XML

See Extensible Markup Language.