I wanted to discuss the technology behind Twilio. I have been playing around with the service for a few days now and it is simply mind-blowing. While I don't have a direct need for it right now, I am curious to find the back-end of the technology.
So can anyone shed some thoughts on how does Twilio do its magic?
I don't know the exact platform Twilio uses. Some of the services that are similar to Twilio are Asterisk based but from the cursory look at the Twilio docs I don't think they are.
If it's features, as oppossed to usability or some other non-functional aspect, of Twilio that impressed you then you should check out Tropo, it's currently head and shoulders above the other voice application services. It's a beta service from Voxeo and unlike Twilio is free for developers AND supports SIP.
I keep a list of all the services I come across at SIP Application Services, as the title suggests I'm mainly interested in ones that support SIP which may or may not matter to you.
Twilio is Asterisk based and hosted in the cloud. You can check out this presentation on Slideshare for more info on our architecture (starts at slide 8 I think).
The Twilio API is free to developers, you only pay for usage when you upgrade to a paid account. Our trial accounts get a $30 credit to start (1,000 free minutes) and more if they need it.
Email us anytime at [email protected] if you have questions, or feel free to post 'em on here. Cheers!
-Danielle @ Twilio
Something is seriously wrong with this picture - go to Twilio.com and go to Tropo.com... anyone else is seeing doubles?! Voxeo seems to be in the copycat mode here...
Back to the subject of the question - from what I know Twilio uses Asterisk as the core of it's services, but they have written a lot of new stuff. That's why @sipwiz doesn't think they are based on Asterisk. The TTS engine sounds like FreeTTS I've used in the past on my own asterisk implementations. It's not the best out there, but does the job and like the name suggests - free. Not sure what they use for speech recognition though.
I have to admit that I'm a fan of Twilio - we currently route significant amount of traffic (in tens of thousands minutes per month) through them and so far nothing but good. The team is super responsive and a pleasure to work with.
I've been using Twilio for about a year now. It was reasonably easy to set everything up. I probably wouldn't have been able to put telephone into my application without them. I've spoken with most of their competitors and none of them seem to be able to compare to Twilio's service, price and usability.
I did speak with one of the founders on the phone once. He mentioned that Twilio runs on Amazon EC2 and that he had a PhD in Cloud or Parallel computing or something like that. I was impressed that he had those credentials and at the same time also seemed to know a lot about customer service which is a completely different and toothful animal.