Acronym: ASR
Expansion: Advanced Speech Recognition
An ASR enabled voice application is able to recognise spoken words.

Acronym: CDR
Expansion: Call Data Record
A record generated by a PBX or other telephony switching device, containing information about a call that it has handled. The records may be written to a file, transmitted out of a serial port or transmitted via ethernet using a TCP socket etc.

Acronym: COA
Expansion: Certificate Of Authenticity
A label that should be stuck to every OEM built Windows PC showing that the pre-installed Windows software is genuine and legitimate. The COA shows a copy of the "Product Key" which is an alpha numeric code in a 5x5 format (5 blocks of 5 chars). The product key needs to be entered during the installation of Windows.

Acronym: CPE
Expansion: Customer Premises Equipment
This term is usually applied to the connection at one end of a communication cable and it identifies the type of interface that is required, or is installed, at that end of the cable. In many instances, the communication protocols used for transmission of data and signals are not symmetrical - that is the equipment at one end of the cable will respond in a slightly different way to that at the other end. Terms like CPE are used to clearly identify which connection type is expected at either end of a cable. One end would be CPE and the other end would probably be "Network" or "Central Office". In the case of digital trunks, such as primary rate ISDN, the equipment at one end of the cable would be TE and at the other end it would be NT. TE, which stands for Terminal Equipment, is another term for CPE. NT stands for Network Termination. The equipment at the local exchange is NT and the PBX at the customer's premises is TE (or CPE).

Acronym: DNIS
Expansion: Dialled Number Identification System
Generically, DNIS is the mechanism that allows a PBX to know which number the caller dialled on an incoming call. The specific implementation of DNIS is likely to be embedded within the communication protocols used on a digital trunk and will be contained in the call setup messages carried on the D channel. DNIS is used in situations where a variety of calls are all being delivered down the same digital trunk to a PBX, an IVR or some other type of CPE terminating equipment. When a call first arrives at the PBX, the receiving equipment uses DNIS to examine the dialled number and uses this to determine how each call should be routed. This is very commonly seen in business telephone systems where individual members of staff have been allocated a direct dial number (see DDI and DID). IVR systems need to use DNIS to determine the dialled number and thereby allocate incoming calls to the correct IVR service.

Acronym: ERP
Expansion: Enterprise Resource Planning
Enterprise Resource Planning systems (ERPs) integrate (or attempt to integrate) all data and processes of an organization into a unified system. A typical ERP system will use multiple components of computer software and hardware to achieve the integration. A key ingredient of most ERP systems is the use of a unified database to store data for the various system modules.

Acronym: FXO
Expansion: Foreign eXchange Office interface
Refers to an analogue telephone connection that is the equivalent of the plug on the end of the lead coming from your phone. It is the connection interface provided on analogue Subscriber Equipment and you connect it to an FXS interface (typically the socket on the wall). The Subscriber Equipment receives and uses services from the local exchange (or Central Office) and it provides on-hook/off-hook indication by closing/opening the loop to allow loop current to flow through the circuit. See also FXS

Acronym: FXS
Expansion: Foreign eXchange Subscriber interface.
Refers to an analogue telephone connection that is the equivalent of the socket on the wall that you plug your phone into. It delivers services from the local exchange (or Central Office). You connect Subscriber Equipment to it. An FXS interface provides Battery Current, Ring Voltage and Dial Tone See also FXO

Acronym: IMP
Expansion: Instant Messaging and Presence
For example, MSN

Acronym: JMS
Expansion: Java Message Service
Java Message Services (JMS) provides a standard, portable way for Java programmers to access MOM products. JMS portability is assured through a well-defined set of interfaces along with a standard reference implementation.

Acronym: LAN
Expansion: Local Area Network
A Local Area Network is the high speed data network that exists within one office or one building and to which computers belonging to one organisation are connected. Connections to the Internet or to other offices or other organisations are provided by a gateway (or gateways) on the LAN. Computers on a LAN have a largely unrestricted access to each other, but connections from the LAN to the outside world are likely to be tightly controlled and should normally be protected by a firewall.

Acronym: LCR
Expansion: Least Cost Routing
An automated mechanism for selecting a carrier or service provider for an outbound call in such a way that the selection results in the lowest cost for the call.

Acronym: LSB
Expansion: Linux Standard Base
The goal of the LSB is to develop and promote a set of standards that will increase compatibility among Linux distributions and enable software applications to run on any compliant system.

Acronym: LVS
Expansion: Linux Virtual Server
Load Balancing software that runs on a Linux server and allows a number of "real servers" to all be accessible through a single "virtual server". Clients wishing to use the service would connect to the "Virtual IP address" which would initially route them to the Virtual Server. The Virtual Server then forwards the request to one of the real servers. Which real server depends on the chosen load balancing strategy. LVS is capable of remembering some state information thereby allowing it to direct related requests to the same real server as was initially selected.

Acronym: MGCP
Expansion: Media Gateway Control Protocol
See RFC 2805

Acronym: MOM
Expansion: Microsoft Operations Manager
A central management tool for monitoring the health of PC's on the LAN and responding to problems as they arise. Special integration packages are available for some Microsoft server products such as Exchange and MS-SQL server. Third party interfaces are also encouraged. The product includes a knowledgebase as well as the performance and event monitoring and reporting tools.

Acronym: MOM
Expansion: Message Oriented Middleware
Helps to describe a category of software that allows completely different applications to communicate with each other through a message queue. Message queuing systems are available from Microsoft, Sun, IBM and others. The queue can be persistent (disk based) or just memory based - the latter is much faster but information would be lost if the message queuing server failed or was shut down.

Acronym: NAT
Expansion: Network Address Translation
A facility that is normally built into hardware firewalls to allow multiple private IP addresses on the LAN to all share access to the Internet through one public IP address. In addition to providing highly efficient use of IP addresses, NAT also has the advantage that it makes computers on the LAN more secure because they cannot be directly addressed from the Internet. However, this can also be a disadvantage for some services that want to be able to communicate directly to a computer - for example Voice Over IP telephony.

Acronym: POTS
Expansion: Plain Ordinary TelephoneS
A commonly used term that generically describes the whole family of conventional analogue telephones such as those still found in most homes. Phones that work on the long established technology whereby current flows through a pair of copper wires connecting the phone to the local exchange (or Central Office). The local exchange provides power to the line in the form of a DC voltage across the pair of wires at a level that is high (e.g. 35V) when the phone is on-hook, but which falls to a lower level (e.g. 8V) when the phone is taken off-hook. When the phone is taken off-hook it actually closes a switch thereby allowing current to flow in the circuit - this is referred to as Loop Current. Ringing is sent from the local exchange down the pair of wires in the form of a relatively high AC voltage (e.g. 60V AC) and causes a bell - or the modern equivalent of a bell - to ring in the phone. When the handset is lifted, the exchange detects the Loop Current and knows the phone has been answered so it stops sending the ringing voltage.

Acronym: SALT
Expansion: Speech Application Language Tags


Acronym: SAM
Expansion: Software Asset Management
Services and applications that exist under the heading of Software Asset Management are used to identify, catalogue and control all the software installed on the computers on a network. Some kind of Software Asset Management is essential in business organisations of all sizes to ensure that unlicensed or risky applications are not being installed by unsupervised employees because such actions potentially put the entire organisations IT systems at risk.

Acronym: SAP
Expansion: Session Announcement Protocol


Acronym: SCN
Expansion: Switched Circuit Network
Example - a telephony trunk

Acronym: SDP
Expansion: Session Description Protocol
See RFC 2327

Acronym: SG
Expansion: Signalling Gateway
For example the D channel in ISDN

Acronym: SGCP
Expansion: Simple Gateway Control Protocol
Defines the interface between a telephone network and VoIP network

Acronym: SIP
Expansion: Session Initiation Protocol
See RFC 3261

Acronym: TDM
Expansion: Time Division Multiplexed
This is one method by which multiple streams of data are combined together into a single stream of data for transmission down a cable or optical fibre. The combined streams may then be separated out again into individual streams at the far end of the cable as required. When digital data is merged using time division multiplexing, the resulting merged data stream is structured as a series of small blocks, called timeslots, within a series of larger blocks called frames. Each timeslot contains a fragmented sample from one of the input data streams and one frame carries the complete group of timeslots representing all the input channels. The structure of a frame is fixed and it is of a fixed length, so the required bandwidth for transmission of TDM data can be calculated in advance and does not vary even if some of the input streams are idle or have no signal. One timeslot is normally assigned to carry one channel of data, but it may also be reserved for synchronisation to make it easier for the receiving equipment to recognise where each frame starts and ends. At the receiving end, the data within the timeslots is extracted and the original individual signals can be reconstructed. The use of TDM inevitably introduces a slight time delay because of the way the data has to be chopped up and re-assembled. In telephony circuits TDM is very widely used for the transmission of multiple individual telephone conversations down a single cable or optical fibre. European standards define a standard rate for transmission on E1 primary rate trunks that provides for 30 voice channels. A total of 32 time slots are allocated within each frame of data - 30 time slots for the 30 voice channels (B channels) plus 1 time slot for the data channel (D channel) and one synchronisation time slot. The total bandwidth required for E1 is 2.048Mb/s. North American standards are different and here the most widely used standard for digital telephony trunks is T1. T1 has 24 time slots and requires a bandwidth of 1.544Mb/s.