I want to pass data between a Python and a C# application in Windows (I want the channel to be bi-directional)
In fact I wanna pass a struct containing data about a network packet that I've captured with C# (SharpPcap) to the Python app and then send back a modified packet to the C# program.
What do you propose ? (I rather it be a fast method)
My searches so far revealed that I can use these technologies, but I don't know which:

JSON-RPC 
Use WCF (run the project
under IronPython using Ironclad)
WCF (use Python for .NET)
Why not use a simple socket communication, or if you wish you can start a simple http server, and/or do json-rpc over it.
IPC between Python and C#