Ask Slashdot: Linux and Telephony

This one is a doosy. I've received various submissions from people who were looking for information on how to make their Linux box into an answering machine. I've also received submissions asking about Voice Synthesis and Speech-To-Text. I have to admit I haven't found much information on either while browsing on the net, so I'm turning the question over to you folks. However I wonder if there isn't a issue hidden here? Can Linux be used as an Interractive Voice Response(IVR) platform? If not, why not? First off, let's NOT forget the actual questions:

Metiu and Sri both want to know if a Linux box with a voice modem can be used as an answering machine.

Gextyr is looking for information on Voice Synthesis packages that are available for Linux.

This Clan AC Member wants to know if there are any applications or APIs for Linux that deal with Speech-To-Text or Text-To-Speech.

Lastly, there have been quite a few submissions asking whether or not Linux can be used as a demand fax server. Can it?

If Linux can be used for all of the things above, what's stopping it from performing as an IVR system? IVR systems are simply systems designed to use a telephone as the computer interface (using both touch tones and voice). IVR systems are used everywhere, from your voice mail, to ordering systems, and corporations are adopting more and more IVR systems for various tasks.

I've seen IVR implemented on DOS systems but most of these have moved to NT. What's preventing Linux from operating in this market? Are there existing IVR projects in progress, or is this another area where Linux falls behind?

Comments

Linux IVR

[tgd]

Its very possible.

I've currently got an old 486/50 DX running Linux 2.2.5 at home that handles voicemail for me using mgetty and some custom shell scripts. (Unfortunately I was never able to get get vgetty perl module working... its very old and there's almost no docs for it...)

Its pretty slick. People calling can leave voice messages or faxes. I've got it set up so either one gets packaged up in a mime attachment to my e-mail and queued to send to me. Next time the system is online it sends them off. If they sit there more than two hours it'll dial itself up and send them and get back offline. Also archives them so I can get them through a web browser on any systems in my apartment, or I can just hit the reset switch on the front of the system (which is plugged into the parallel port) and it plays any new messages for me. The turbo light blinks when I've got new messages.

I can also control all the X10 stuff in my apartment (mostly useful for options #1 -- turn off all the halogen lights, and #2 -- turn of coffee pot, both reducing the chances that my spacing out one morning will result in my apartment burning down) ;)

Last thing I can do is use it to cause my network to dial up. The system handles my masquerading and internet access as well as voicemail, so when it dials up my entire network is online, then it e-mails the IP address it got to my PCS phone. Secure SLL webpage on that IP address lets me control all those devices directly (especially turning on other PCs), check my messages, or disconnect the network...

The real limiting factor I'd see in using it as an IVR system is more limited support of multi-line voice products, and the poor documentation and difficult programming for vgetty. I'm not sure there are any options other than vgetty.

Using vgetty in combination with packages like HylaFAX gives you easy ability to do fax-on-demand and other services like that.

I also used a system with three 14.4k voicemodems and vgetty as a way of validating information on a system that required the user give their true phone number. User was e-mailed a code to punch in after storing their supposed phone number and that code in a database. The voice system would use caller id and compare the code they entered with the code matching that number in the database. Match? Voila! Flag is set, account is activated.

Worked great, client never used it though. C'est la vie.