VOIP: How to Create a Web app to make Call like skype or msn ?

Question

This is a very newbie question.

I want to know how to create a WEB APP to make Call ( using VOIP protocoll I think ).

What program languages do I have to learn ( client and server side ) ?

Answer 1

You may wish to purchase a component which allows you to add SIP functionality to your webpage, (most of these ones are ActiveX based):

http://www.conaito.com/
http://www.vaxvoip.com/
http://www.pcbest.net/

As for the language you have to learn, well what languages have you learned already? Which languages have you developed web apps with? This determines your choice of language. Using components like those listed above take some of the legwork out, but still will require probably vbscript or javascript coding client side, and those that are activeX will only work on Internet Explorer webbrowsers. If you have no experience then you need to look seriously at what you are trying to do, why, how much time and effort you can and are willing to put in.

Answer 2

Gizmo5 has a Flash softphone that runs in the browser: GizmoCall On the server side, you'd probably link it up with an SIP solution in any language. Asterisk comes to mind, although it may be a bit overkill depending on whether you really wanted a full-blown SIP solution or not.

Answer 3

The answer to your question really depends on what you want to do with it. Here are 2 examples of how I have gone about it:

I developed the software for Go2Call.Com (now owned by Deltathree), and it was used for PC-to-Phone calling. In Go2Call's case, it was a Java applet for the dialer frontend that called a Windows DLL written in C++. From there, it spoke a proprietary protocol to talk to the servers which in turn sent the call to regular landlines.

A few years later, I wrote a web-based (ActiveX control) that would allow PC-to-PC or PC-to-Phone calling, and it used the standard H.323 protocol.

I would recommend starting out by figuring out what your end goal is and then looking up the necessary protocols and technologies to accomplish it.

For PC-to-PC, you can do whatever you want if both people use your software. In that case, you can figure out how VOIP works (including compression codecs, etc.) and implement it however you want.

For PC-to-Phone or when you want to call someone else's software, I'd recommend SIP since it's probably the most popular protocol. H.323 is still prevalent, but SIP seems to be taking over.

Sorry this doesn't probably tell you everything, but there's a lot to it. Hopefully, this will get you started in the right direction.

Update: Since you mentioned PC-to-PC, Packetizer has a list of standards and quite a bit of info I used way back when I did a lot of VoIP programming.

As far as books go, the books I've seen so far aren't programming-related but more about using VoIP software and installing VoIP networks.

Answer 4

The primary question you need to answer to get started is are you looking for a computer to computer call or do you want your app to call a telephone number?

Since you specify that you want your "web app to make a call," I suspect you're looking for a way to place automated calls to a user's telephone. If that's the case, you've got a few options.

Install a VoIP server like Asterisk or Freeswitch and write code to have your web app interact with it. For Asterisk, the Adhearsion project can help by allowing you to write Asterisk integrations in Ruby. http://adhearsion.com/

Or you can use a cloud telephony service like Cloudvox or Tropo http://tropo.com (disclosure, I work for Voxeo, the company behind Tropo). These services allow you to use web programming languages and web services to talk to the phone system. You don't need to know anything about Voip to make it happen. A sample Tropo script...

<?php
answer();
say('Yes, it really is this easy.');
hangup();
?>

A side benefit to the cloud services is many of them allow your app to run over other communications channels (Tropo does IM and SMS, too).

The third option is to look into VoiceXML, a W3C standard for creating voice apps. Voxeo provides detailed docs and VoiceXML tutorials at http://vxml.org/. With a VoiceXML (sometimes called VXML) application, you can install a VoiceXML server and the associated VoIP bits or you can use a VoiceXML hosting provider. Voxeo provides both a downloadable server and hosting (both are free for developers), or a search for VoiceXML hosting will reveal a large number of options.

Answer 5

Hi all!

Glad to present Flashphoner. Flashphoner is a Flash-SIP server gateway, which allows to create your own flashphones and click2call services. I allow stream media traffic from RTMP server to VoIP server.

Server: Transcoding Speex <-> G.711, Transcoding Sorenson Spark <-> H.263, Connect RTMP<->VOIP, Support SIP 2.0, Support DTMF,

Client: Flashphone (open source), Click-to-Call button (open source), Java Script API,

Please write here [email protected] all the comments functionality. All suggestions will be considered.