LiveTool, P2P experiment in Javascript

I have been working in the last month in a project called LiveTool which was an experiment of how it would be possible to use P2P communication in a Javascript application. The project in itself can be found on GitHub : https://github.com/HoLyVieR/LiveTool

In brief, the project was a graphic editor that could be used by multiple people at the same time and people could see all the modification that where done as soon as they are made.

What where the obstacle ?

One of the main obstacle in starting this project was that RTMFP is not a well known technology and the documentation is very limited. In fact nearly everything you will found about it is made by Adobe. Also, the way RTMFP works in Actionscript is not very intuitive. Also when I wanted to start this project, I couldn't find any Javascript library that would allow me to use RTMFP without doing any Actionscript. This is the main reason I builded the RTMFP-JS library.

What about support for people that don't have Flash ?

This is a point I wanted to experiment with the project. Using P2P communication is very interesting, but it isn't widely supported so you still have to think about integrating fallback for those that don't support it. Technically speaking it isn't hard to implements, but if you don't integrate it from the start, it can be very hard to do. The fallback that I implemented for LiveTool is very simple, if you don't support RTMFP or if you want to send data to someone that doesn't support RTMFP, the server is used as a repeater.

Will LiveTool have more updates ?

For now, I'm leaving the LiveTool project as it is now, since I got to the point where I did the experiment that I wanted to do with it.

What about ... ?

If you have question about the project, you can leave a comment and I will try to respond to you or do a blog post about it.

P2P and Javascript

I have been experimenting  P2P connection with Javascript (in the browser) over the past few months, it's been quite interesting and it has revealed to me that it could have a lot of potential.

How do I do P2P communication in Javascript ?

You probably won't hear about P2P communication and Javascript a lot, because there isn't any native API that will allow you to have direct connection with other client. But it is supported through a common 3rd party plugin : Flash. Inside Flash you can use a protocol called RTMFP which allows P2P connection. If you want to read up about it you can have more information on adobe website.

But you said with Javascript, not Actionscript !

The nice thing about Flash, is that you can communicate with Javascript through ExternalInterface. With this we can use Flash technology but with Javascript and we don't have to create a Flash application to use RTMFP. If you don't really care about the Actionscript / ExternalInterface part, you can use some already made library which will take care of it. I builded up my own which is available on Github : https://github.com/HoLyVieR/RTMFP-JS-Bridge

Why should I use P2P communication ?

P2P communication is mainly aimed for application that require that multiple client speak to each other. One of the basic example of that kind of application would be a chat. All the information that are sent between the client won't have to pass through the server. It reduces traffic and load on your server since you are now sending and receiving less data while doing the same thing.

Why shouldn't I use P2P communication ?

There are 2 principle obstacle to P2P communication. Network infrastructure and Flash support. If you are inside a corporate or school network, there's a strong chance nobody will be able to connect to you because of the way the network you are in is made. As for the Flash support, it isn't supported on some mobile platform and even tough there is a larger proportion of the Internet user that have it, some don't have it for various of reasons ( OS support, they don't have admin rights on their machine, etc. ).

What about security ?

The RTMFP protocol informations are quite vague or hidden, so it's hard to say how secure the protocol is, but from what Adobe has written so far it seems that the information that is exchanged between the client is encrypted.

The only certitude that you can have is that the information that a client will receive will be from untrusted source (an other client, not the server), so you have to implement the same information checking that your server would have, but on the client.