Why don't you speak in the thread you were talking about this anymore? Man, it isn't useful, it's something do you want to have fun with. It's like I say... I want a U.R.A.Q.T app with girls. That doesn't help us.
An application that simulates network traffic sent between a 3DS and Pokémon's servers? Why not just use a packet sniffer?
Whoops, looks like OP wanted a Wonder Trade generator. Ethical issues aside, it would mean having to decrypt the packets from the game and re-encrypting your own custom data and then sending it to the server. Even if that were achieved, the software still needs to fool the server into detecting the PC as 3DS hardware running a legitimate Pokémon game. While it's theoretically possible, it would take a lot of work, and may involve the use of (possibly) illegally implementing code extracted from ROMs.
So everyone sayinh this is impossible. You guys are wrong.
Everyone who has ever dealt with netwrok traffic. Specifically online game packets will know it's possible.
What do you guys think how people create private servers? They analyze the network traffic, get the packet structures worked out. Redirect them to their own server and slowly try to recreate a server. (Usually after breaking encryption).
Mystery Gift Servers can be emulated as well. (Has been done)
"System spoofing" is not necessary at all. It's done by packets anyway.
However I personally don't think it's worth the hassle.
Even experiences people would probably take multiple days to break the encryption and recreate a working tool.