how to make call from pc using local landline phone services

Question

I have a desktop application of address diary, developed in C# .Net.

I want to make call from software throw land line phone service, in my office we have 8 phone lines, so i want to select line before call, i want to use headphone and mic in place of phone instrument.

how to connect phone lines to pc. i have more then 8 phone lines

is it possible ? if yes then how and which hardware i need for this.

Answer 1

Have you thought of the Skype API: http://developer.skype.com/public/skypekit or http://www.twilio.com

Get rid of the landlines and use a service. Much easier in my opinion. Then it would be far more scalable as well.

If you want to go down the telephony services path check out this library: https://github.com/markjulmar/atapi.net/

Hardware for landlines would just include 8 modems and selecting which one to use, before making a call.

I would assume that the atapi library contains functions to select the audio input and output. If not there are plenty of c# libraries for recording audio, in which you could pass the stream through to the library.

I wasn't going to point you down this direction but as per @Saif Khan comment you can use Asterix.

Using Asterix

Step 1 - Get a server install Asterix on it. http://www.asterisk.org. It's open source.

Step 2 - Get supported hardware e.g. http://www.asterisk.org/hardware

Step 3 - Communicate to it with http://sourceforge.net/projects/asterisk-dotnet/ (open source c# to asterisk library.

This maybe overkill for you, I don't know. I suppose I shouldn't assume :)

Answer 2

Since Google Voice is still free in United States and Canada. You can use this Google Voice API in C#.

http://sourceforge.net/projects/gvoicedotnet/

Answer 3

Doesn't want to sound like a noob, but did you try out Windows Dialer? You will need x number of 56k dialup voice modem depending on the no. of connections you have and you want to use.

It should work just fine. Test it out, and if it works well, you can get your app synced with your existing software to export the number to the dialer upon calling. (There is no such functions on the dialer app yet.)