Asterisk AGI framework for IVR; Adhearsion alternative?

Question

I am trying to get started writing scalable, telecom-grade applications with Asterisk and Ruby. I had originally intended to use the Adhearsion framework for this, but it does not have the required maturity and its documentation is severely lacking. AsteriskRuby seems to be a good alternative, as it's well documented and appears to be written by Vonage.

Does anyone have experience deploying AGI-based IVR applications? What framework, if any, did you use? I'd even consider a non-Ruby one if it's justified. Thanks!

Answer 1

There really aren't any other frameworks out there. There's of course AGI bindings to every language, but as far as full-fledged frameworks for developing telephony applications, we're just not there yet. At least in the open-source world.

Answer 2

I have asked somewhat related questions here, here, and here. I'm using Microsoft's Speech Server, and I'm very intested to learn about any alternatives that are out there, especially open source ones. You might find some good info in the answers to one of those questions.

Answer 3

If you're looking for "telecom-grade" applications, you may want to look into SipXecs instead of asterisk. It's featureful, free, and open source, with commercial support available from Nortel. You can interact with it via a Web Services API in ruby (or any other language).

See the SipXecs wiki for more information. There's a comparison matrix on that site, comparing features with AsteriskNOW and TrixBox.

Answer 4

SipX is really the wrong answer. I've written some extremely complicated VoiceXML on SipX 3.10.2 and it's been all for naught since SipX 4 is dropping SipXVXML for an interface that requires IVRs to be compiled JARs. Top that off with Nortel filing bankruptcy, extremely poor documentation on the open-source version, poor compliance with VXML 2.0 (as of 3.10.2) and SIP standards (as of 3.10.2, does not trunk well with ITSPs). I will applaud it for a bangup job doing what it was designed to do, be a PBX. But as an IVR, if I had it to do all over again, I'd do something different. I don't know what for sure, but something different. I'm toying with Trixbox CE now and working on tying it into JVoiceXML or VoiceGlue.

Also, don't read that SipX wiki crap. It compares SipX 3.10 to AsteriskNOW 1 to Trixbox 1. Come on. It's like comparing Mac OS X to Win95! A more realistic comparison would be SipX 4 (due out 1Q 2009) to Asterisk 1.6 and Trixbox 2.6, which would show that they accomplish near identical results except in the arena of scalibility and high-availability; SipX wins at that. But, for maturity and stability, I'd advocate Asterisk.

Also, my real world performance results with SipXVXML:
Dell PowerEdge R200, Xeon Dual Core 3.2GHz, handles 17 calls before jitters.
HP DL380 G4, Dual Xeon HT 3.2 GHz, handles 30 calles before long pauses.

I'll post my findings when I finish evaluating VoiceGlue and JVoiceXML but I think I'm going to end up writing a custom PHP called from AGI since all the tools are native to Asterisk.

Answer 5

You should revisit Adhearsion as v0.8.1 is out, and the documentation has gotten much better quite recently. Have a look here:

http://adhearsion.com http://docs.adhearsion.com http://api.adhearsion.com

Answer 6

I used JAGIServer extensively, even though it's not under development anymore, and it's pretty good and easy to use. It's an interface for FastAGI, which I recommend you use instead of simple AGI.

The new version of this framework is OrderlyCalls which seems to have a lot more features but since I haven't needed them, I haven't tried it.

I guess it all depends on what you want to do with AGI; usually I have a somewhat complex dialplan to gather and validate all user input and then just use AGI to connect to a Java application which will read some variables, do some stuff with it (perform operations, queries, etc etc) and then sets some more variables on the AGI channel and disconnects. At this point, the dialplan continues depending on the result of the variables set by the Java app.

This works really fast because you have a ServerSocket on the Java app, which receives incoming connections from AGI, creates a JAGIClient with the new socket and a new instance of a JAGIProcessor (which you have to write, it's the object that will do all your processing), and then run the JAGIClient inside a thread pool. Your JAGIProcessor implements the processCall method where it does all the work it needs, interacting with the JAGIClient passed as a parameter, to read and set variables or do whatever stuff the AGI interface allows you to.

So you have a Java app running all the time and it can be a simple J2SE app or an EE app on a container, doesn't matter; once it's running, it will process AGI requests really fast, since no new processes have to be started (in contrast to simple AGI which runs a program for every AGI call).

Answer 7

Smee again. After migrating my client's IVR's over from SipX to Asterisk utilizing PHPAGI, I must say that I haven't encountered any other architecture that anywhere near as simple and capable. I'll be stress testing Trixbox CE 2.8 today on the same hardware I had tested SipX on earlier. But I must say, using PHPAGI for the IVR and the Asterisk CLI for debugging has worked perfectly and allowed me to develop IVR's far faster than any other company out there. I'm working on implementing TTS and ASR today and I'll post my stress test results when I can.

Answer 8

Simple small flexible Asterisk AGI IVR written on PHP http://freshmeat.net/projects/phpivr

Answer 9

For small and easy applications I use Asterisk::AGI in perl. There are also extensions for the Fast AGI. For bigger applications, like VoIP operator's backends I use something similar to OrderlyCalls written in Java (my own code). OrderlyCalls is great though to start with java fastagi engine and extend it to your needs.