Telephone Alerts | WebReference

Telephone Alerts


Telephone Alerts

Modems, My BBS, and Vgetty

The Black Knight BBS

I've been thoroughly intrigued by modems and computer telephony since I fired up my very first modem. I had been having great fun playing games like Exploding Fist on my Commodore 64 when I decided to look into these modem things at the local Best department store. After bringing my new toy home and ripping the box open, I pulled out a small light grey box, plugged into the back of the computer, and plugged it into a phone outlet. There was also a floppy disk that said Q-Link on it. I fired up the disk, and was soon signed up and browsing chat rooms and playing black jack online. it was cool but expensive. After racking up a few large phone bills from playing too much Battletech with other Q-Link users, I decided to look into Bulletin Board Systems. After hacking around on the local college VAX, I discovered the Color 64 BBS, upgraded to a 2400 baud Hayes modem, and started my very own BBS called Black Knight. Since then, I've had many modem adventures that have now led to the Internet and on to the point of this article.

Vgetty and Linux

Vgetty is an application that allows you to receive incoming voice calls or make out-going voice calls. It's often used as a simple answering machine. Most linux distros these days come with vgetty already installed, though it should work on any Unix variant. More information about vgetty is available at I've been playing with vgetty off and on for a couple years now with varying levels of success. Until recently, there was little or no documentation on how vgetty actually works, much less a Perl module. More recently, a couple programmers have posted code and modules to work with vgetty. But before you can play, you'll need a modem that's capable of handling voice data. Personally, I used the US Robotics (now 3Com) Sportster voice, but any modem listed on the vgetty page will do.

Vgetty Alerts in Perl

The Modem::Vgetty module, written by Jan "Yenya" Kasprzak and available on CPAN, works fairly well. So for this article, I whipped up a couple examples where a phone call is placed and a voice file played based on a pre-defined event. it could come in handy for many different applications, so I will keep the examples fairly abstract and let you fill in the pieces.


Produced by Jonathan Eisenzopf
Created: October 12, 2000
Revised: October, 2000