websocket server minimum requirements

Question

I know websocket is a protocol, so it shouldn't depend on any operating system requirement as it happens to communicate via ftp or http. I found different libraries to use this protocol, but they seems to have requirements for .Net 4+ (no Windows XP), Visual Studio 2015 at least (so at least Windows 7) and often there's no requirement... until I try to compile or run the example of a certain library (after installing whatever it takes to compile it) and I get runtime errors about invalid parameters, something not supported, wrong this and wrong that.

After days of theese trials and errors, I decided to ask this strange question: there's a way to use such protocol with an older operating system, such as Windows XP or an old version of linux? I found every detail for browsers support, but obviously it is only for the client. Node.js for the server, written in js, can be used even with old computers and operating systems?

I cannot find anywhere what are the minimum requirements to write a server listening on a websocket (it's a protocol so it is not too hard to believe I found nothing :/ ) and I need to make deduction by languages or framework requirements (eg. .net 4+, so not Windows XP).

I'd like to do RPC with websocket but I cannot run server of WAMP (https://stackoverflow.com/a/10882808/1315873) in Windows XP and Visual Studio 2010 (it run perfectly on Windows 7 under Visual Studio 2015).

I can use other languages to accept connection on websocket... the other part of my software is written in .net 3.5 so I need to find something not to hard to call from and to .net 3.5.

Thank you for any help or explaination.

Answer 1

The only system requirement for writing a webSocket server is that you have TCP and can set up a TCP server, listening for incoming connections. webSocket is just a protocol on top of TCP.

webSocket connections are technically initiated with an HTTP request, but the part of HTTP that you need is extremely simple (just parse a few incoming headers to identify a security credential and the request to upgrade to the webSocket protocol) and once both sides agree on the upgrade, then the protocol is switched to webSocket and HTTP is not used any more on that connection.

What you are likely discovering is that the webSocket libraries you are looking at are themselves built on top of other libraries (such as .NET) which creates a dependency on those other libraries. That is purely a by-product of their implementation, not a requirement of the protocol in any way.

So, yes it is certainly possible to write a webSocket server that has no external dependencies other than a TCP library and that could easily run on Windows XP.