Business telecommunications and IT systems

The T-series Recommendations from the ITU-T regarding terminal equipment and protocols for telematic services.

An ISDN term.

The interface between the PTO's NT1 and the NT2.

The USA standard term for an ISDN PRA circuit.

In the USA, a PRA ciruit is different from that in Europe, with only 23B + D channels.

Q.931 signalling is used with a total bandwidth of 1.544Mbit/s.

The connection point for an PRA circuit.

see Terminal Adaptor.

see Telecommunication Advisory Committee.

A Telephony slang term for an LJU Adaptor.

A BT term.

The period between a payphone demanding a coin and disconnecting the call if no coin is inserted.

The abbreviation for Telephone Answering Machine.

Where three or more telephone system CPUs are linked by private circuit connection, enabling direct dialling from one CPU to another via any of the others, transparently.

For example, if three CPUs are connected in a row, a call from the first to the third will pass straight through the second as though it wasn't there.

A form of high capacity storage, typically used to back up hard disks.

Telephone Application Programming Interface for computer telephony integration.

Allows PCs running Windows to use telephone services, such as hold, transfer, conference, and call park.

Backed by Microsoft.

see TAPI 2.

Supports 3rd party call control in a Windows NT environment.

See TAPI.

see Time Break Recall.

BRA specification, set by ETSI.

PRA specification, set by ETSI.

A Frame Relay term. Committed Rate Measurement Interval (secs).

The time interval during which the user can send only Bc committed amount of data and Be excess amount of data.

In general, the duration of Tc is proportional to the 'burstiness' of the traffic. Tc is computed from the subscription parameters of CIR and Bc, as Tc = Bc/CIR.

Tc is not a periodic time interval. Instead, it is used only to measure incoming data, during which it acts like a sliding window.

Incoming data triggers the Tc interval, which continues until it completes its commuted duration.

A BT term. Target Completion Date.

The date BT is expecting to provide service to a subscriber.

Transmission Control Protocol / Internet Protocol.

The name applied to a popular protocol suite developed by the Defence Advanced Research Projects Agency (DARPA.

TCP is the transport layer in the suite and IP covers layer three.

Now also used on many private networks.

Time Division Duplex.

A DECT protocol.