Business telecommunications and IT systems

An ISDN term.

The interface between the telephone system and an S0-bus.

An ISDN term.

The interface between the NT1 and the TE1s on an S0-bus.

The cabling which runs from a BRA Line Box within the customer’s premises, to which terminal equipment is attached.

Depending upon the bandwidth a terminal requires, it may use one or both of the two Bearer channels at any one time.

If only one channel, then another device can use the other. Hence, different terminals must compete for access to the So-bus.

The suffix '0' is a zero, and refers to the last digit of I.420, indicating I.420 signalling which in turn indicates BRA.

The cabling which runs from a PRA Line Box within the customer’s premises, to which terminal equipment is attached.

Depending upon the bandwidth a terminal requires, it may use one or more Bearer channels at any one time.

The suffix '1' is the digit one, and refers to the last digit of I.421, indicating I.421 signalling which in turn indicates PRA.

see Storage Access Network.

Where the volume of data traffic on a network is close to the maximum it can handle.

Schools Interoperability Framework, also known as Systems Interoperability Framework, is a data sharing open specification for academic institutions.

Abbreviated to SIF.

The specification comprises two parts,

1 An XML specification for modeling educational data
2 A Service Oriented Architecture for sharing data

SIF is not a product but an industry initiative which enables diverse applications to interact and share data.

The specification is actively maintained by its specification body, the Schools Interoperability Framework Association.

The Schools Interoperability Framework Association (SIFA) is a not for profit organisation.

SIFA members collaborate on many technical standards, typically known as the Schools Interoperability Framework.

SIFA publishes these standards and advocates their adoption and provides training and support services.

SIFA also offers SIF Certification.

Single-line Call Routing Apparatus.

see Monitor.

Signal Computing System Architecture.

An open standard Architecture for specifying the interfaces for PC based CTI applications.

Small Computer Systems Interface.

A high speed controller that can co-ordinate up to seven devices, and can also speed up communications with hard disk drives.

Supplier’s Declaration of Conformity.

In April 2001, this document replaced the TEC Annex, which had in turn replaced the PXML.

see Synchronous Digital Hierarchy.

Synchronous Data Link Control.

A transmission protocol developed by IBM in the 1970s as a replacement for its binary synchronous communication protocol.

SDLC is equivalent to layer 2 of the OSI model.

Synchronous Dynamic Random Access Memory.

A fast form of memory.

Symmetric Digital Subscriber Line.

A technology which allows more data to be sent over existing copper telephone exchange lines, supporting data rates at up to 3Mbit/s.

Works by sending high frequency digital pulses not used by normal voice communications simultaneously with voice connections over the same wires.

Requires a special SDSL modem.

Called Symmetric since it supports the same data rate both for upload and download.

see ADSL.

see Extension Socket.

see BT Select Services.

A BT term. Associted with BT's Advanced Features.

Callers direct themselves to the service they want.

Different levels of service can be offered. Calls can be handled on the basis of priority. Reduces the need for live operators to transfer calls.

Reduces the need for private circuits between premises to transfer calls.

Operational costs reduced, calls filtered in the network and not by the customer.