[Tutor] Telephone app

[Alan Gauld]

"David Hutto" <smokefloat at gmail.com> wrote

> No, its just wondering whether it works like the USB, with two data
> pins, and -+, I know how the original works, but interpreting 
> through
> computer language is a little disabling.

The original what?
What works like USB?

A traditional analog line works with a 2 wire signal to the central
switch with a 3 wire signal between stations. All controlled by
hardware analog signalling. If you move to digital telephony
(non VoIP) then you get into a plethory of different signalling
protocols all controlled by the ITU. Which protocol applies
depends on the manufacturer of the switch, the country you
are in etc. ISDN is defined in a standard of its own.
VoIP has a whole different set of protocols, the most common
on PCs is SIP.

If you just want to control an analog phoneline then the esiest
way is  to use a modem and communicate with it via the Hayes
command set over the serial port.

And whatever you do remember that the core of all telecomms
work is a reliable state machine. All telecomms protocols are
stateful to some degree.

But for now its just not clear what you are trying to do.


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/