POTS-Replacement Telephone for The ATM Warren

Download PostScript version here.

Overview

This telephone is a dumb device containing an ATM interface, A-to-D and
D-to-A convertors, hands-free speaker and microphone, keypad, ringer and
LCD display. It requires an external DC power supply and may connect
to either a Warren or a standard ATM25 switch port. A network of
requires an additional control processor. Signalling uses the Warren Control
Protocol and the Warren Audio and Keypad protocols.

Audio Format Options

Link selectable:

VTOA AAL-1, 6 byte fill
44.1 Ksps, L=R mono.

ATM Virtual Channels Used

According to Warren principles, all VCIs are hardwired.
Control cells for off-hook and keypad presses are sent
on VCI=50. LCD and ringing info is received on VCI=50.
Warren command cells for O&M are handled on VCI=30
and VCI=31. Audio is generated and received
on VCI=48

Features

Hands Free
LCD Display
Scrambler Option
No unique ID
Housed in production case
On hook = No Audio interlock
No processor/software inside

The Warren Project

The ATM Warren Telephone is an experimental
hardware device being developed at the University
of Cambridge Computer Laboratory as part of the
Warren Project. The Warren project is funded by Virata
and has the aim of developing a set of low-cost ATM devices.

Pin Connections

RJ45 modular jack:
1 TX +
2 TX -
3 NC
4 DC 0 Volts
5 DC +7.5 to 15 Volts
6 NC
7 RX -
8 RX +

This is the standardised Forum
pinout for an ATM 25 end device,
but with an additional power supply
option.

The ATM Warren Project
University of Cambridge
Computer Laboratory
New Museums Site
Pembroke Street
Cambridge CB2 3QG
http://www.cl.cam.ac.uk/Research/SRG/HAN