The Telecommunications Department
Estate and Facilities Management

Telephone User Guide - Common Features for all University Phones

Connecting
Conventional modems are designed for use with analogue lines only (digital lines need terminal adaptors, not modems). Most of our lines are analogue, and can be used with modems. The modem must be BABT approved, and supplied with a standard BT phone plug; flat with a cliplock on one edge. Note that the modem should have an REN (Ringer Equivalence Number) stated and that the maximum total REN connected to any extension is 4.

Some modems are provided with a phone socket allowing a standard phone to be plugged into them, removing the need for a socket doubler. However, most do not provide BT style sockets, and so adaptors are needed and sometimes supplied. These through systems will allow the use of an attached phone but will often not allow it's bell to ring.

In those areas of the university where telephone connection is provided via "cat 5" wiring systems, the wall socket is an RJ45 type and an RJ45 to BT style converter will have been provided. This must be used if a modem is used on the line. Do NOT plug a phone with an American style connector (transparent, colourless) directly into a university wall socket.

Modem types
Most modems will be desktop units or will be fitted inside a computer either as an expansion card or as a PCMCIA card. (Yes, there are others...) The modem should be supplied with a manual and connection instructions; if not, don't buy it.

Desktop units usually have serial connections to the computer, and provided a suitable connection lead is available can be used with most varieties of computer. Where variants of a modem are available for different computers, it is usually the leads and the software supplied that differ. For USB modems (fast serial), the lead is standard but the software will be matched to the computer.

Card modems are specific to computer type or a computer slot type, a Mac 475 modem will not fit a 486PC, for example.

PCMCIA modems are produced to a common(ish) standard and should work with any machine which accepts these cards and has appropriate software.

In all cases, there are different levels of performance and facility available. However, since they are all designed to work into a standard telephone system, they should all work with our system. Remember that BABT approval is a requirement. Note also that the Class of Service restrictions still apply; if your phone is not allowed international access, using a modem will not remove that restriction.