JJ2 Networking Protocol
 

Hi all,

So recently I got very interested in JJ2 again. I used to play JJ2 when I was around 6 years old or something, and the nostalgia factor alone made me want to play it again.

However, in the 13-or-so years since then I've picked up a few more techy skills:roll: I began analyzing the protocol JJ2 uses to play multiplayer games over the network, with the vague and hopeless idea of eventually writing my own server.

It's been real fun so far, and although I'm not anywhere near a fully functional server, I have decoded a portion of the protocol and am working on decoding the rest.

Then, I stumbled upon this site again for the first time in years. I immediately thought of the possibility of sharing what I learned with others, in the hope of sparking an interesting discussion. Now my question to you is as follows. Do you think it's desirable to have an open discussion about the network protocol here? I can see advantages and disadvantages, since theoretically the information could probably also be used for cheating.

So yeah, that's my question to you all. Is this a place I could post what I find or should I keep it to myself?

Well, you could start talking to a player called Nerd, he sounds a bit like your type ;)

What Jake means: Nerd does disassembly too, not that you're a nerd.

You might want to ask Grytolle for access to the J2NSM wiki, too.

Glad you cleared that up :D Thanks both!
Thanks! What's that stand for?:)

Jazz 2 No Source Modification - we had enough of ppl on this forum saying "it can't be done without the source code"

grytolle@craccoclan.com, contact me on msn

If you have more informations about the struct as written on j2nsm please contact me too, i made once a server in delphi, it was possible to connect and download levels as clients (with a time-out after connecting...,because I never made the udp part :D)
MSN: Daniel.BBB@online.de

Sfaizst

Thanks both! I haven't been on MSN in ages but will definitely boot it up for this ;) Talk to you soon!

EDIT: So far my hackish server has got the following down:

• Responding to local net broadcast
• Responding to pings
• Responding to TCP join requests with server settings, list of already joined players with fur colors and names and all, etc
• Receiving UDP game packets (1 and 8) and parsing them
• Forcing a player to be a certain character, color or name for shits and giggles.

It's been real fun so far.
I haven't looked at the downloading yet, and the more I look at this the more it seems I have to emulate the entire game in order to emulate a server. Not that I mind though:lol:

We have pretty much the entire protocol documented, so unless you very much enjoy figuring it out by yourself, don't waste your time :)

Well, while I would enjoy doing that, having all the information available already would of course also be much appreciated and speed up my efforts by a tenfold :)

I'll try to get on MSN today ;)