The Beginners Guide to p2p kaillera

Guess that title will do

This is a simple step by step tutorial on how to get started with P2P.


Step 1: Set up the emulator

1.1: Get the latest version of your emulator!
for kawaks:
for FBA:

Unzip it to wherever you want to install your emulator!

1.2: Download the p2p client
Download it from
Download it to either your emu’s setup folder (where you extracted the mame executable above) or your C:\Windows\System32 or equivalant folder for global install.
Note: If you are going to put your client in C:\Windows\System32, make sure there is no kailleraclient.dll in your emulator’s folder.

1.3: Configure your emulator
i.e. Set up rom folders and display options and keys and whatnot. Since you know most about your emulator, ill just leave it at that.

Step 2: Set up your connection
Port 27886
You will need to port forward port 27886. i.e. make sure that your modem/router and whatever you might have forwards all UDP packets of port 27886 to your pc. Its the same as if you were configuring your bittorrent client or other any other p2p systems for usage behind your router.

If you’ve never port forwarded before and you’re totally confused, visit
Find your router brand/model no there. Look for the default guide for your router. These are really easy to follow step by step guides designed for those who can read and click.

Also, if you have firewalls and internet access control softwares such as Norton or your windows firewall or [insert name here], be sure to add your emulator program or port 27886 to their allowed/excepted list.

Step 3: Use p2p

The idea behind p2p is really simple. One person hosts and the other person connects.

**3.1: Activate netplay from your emulator. Select the “host” tab if not already selected and you should see the p2p mode screen. **

3.2: To host a game, activate the host tab, select a game and press host
It should show something like this.
To enlist your game in the public waiting games list, tick the “S: Public” checkbox (marked red in above screenshot).
Also note the “whatismyip” button. Use it to determine your external IP as well as to see if the waiting games list server is up.

3.3: Connect through waiting games list.
On the p2p mode screen, switch to the “connect” tab and click on the “waiting games” button. It should open up the waiting games window and automatically download and ping waiting games. You can just double click to connect if you find the game you are after.

3.3: Connect with IP.
If you dont want to use the waiting games list or the waiting games list if offline or when playing in your own local network, you can connect to host with his external IP/hosting port. All you need to do is put his ip in the PeerIP box and click connect.

3.4: The game will start as soon as both users mark themselvs ready (marked blue).

Use this thread for asking questions and whatever
Links & others:
SRK p2p matchmaking: srk kaillera channel @ #srkkaillera on efnet
The bug reporting system: for bug reports and suggestions
Youtube Video tutorial: [media=youtube]L0uVZblgdcE[/media]
Another Youtube Video tutorial: [media=youtube]Ae6Dg40DbF4[/media]
Another tutorial site: asdasda
Kaillera, P2P Kaillera and nFBA:
Port forwarding guides:
Port forwarding help thread:
Website Info, FAQ, Guides:

I have used torrents for a whole now (3 different clients) but I never forwarded a port. In the options menu in each client there would be a default port and I used that. I’m behind two routers… was it normal for BT to be usable all this time under those conditions?

Can anyone join your game via the waiting games list when you host and make your game public? If they can then you don’t need port forwarding.

I’m using the neo/cps build and its not allowing me to start the kaillera client at all. It says that I need an exe in the Kaillera folder when I have the dll there. I know this is a stupid question but I am new to online play.

Edit: Nevermind I figured it out. You have to go and choose the client in Kaillera server options.

So I’m guessing this only works with the newer mames not .64?

edit: nm found an answer, thanks.

I guess it should work more or less with all kaillera enabled emulators. 0.64 was reported to not work with client’s internal playback but that bug is fixed in the WIP builds and mames have their own input recorder recorder =)

Bob, it looks like you tried to “start kaillera server” instead of enabling good old netplay.

yeah port forwarding totally confuses me, and no games show up on the waiting list…

i get an error when i click the box that says “click here when ready” and it says…
ListView_FindItem return -1

I moved this post to a thread with more views.

This needs to be stickied.

I tried and apparently no one could even see my game in the waiting list, nevermind join it. I couldn’t host with the early builds without the waiting list either. I guess torrents must be some exception to the rule.

You’ll need port forwarding behind routers for any kind of incoming direct connection. The thing with torrent is, even if they cant connect to you, you can connect to them and you get a list of peers downloading the same torrent when you contact your tracker. And some routers support UPnP framework which makes it possible to configure supported routers on the fly but thats just adding extra complications.

I just came back from trying it and It kept crashing every time the game started. Is that a symptom of using a different version of mame?

No poundmax i believe it was my modem, I had trouble with it. It kept restarting like every minute but now it seems fine. I guess I should pay my bill :wgrin:

Speaking of paying bills, I shoulda stickied this a couple days ago. Now that my net is back on, consider it stickied.

Nope. And my port is forwarded. As far as I know anyways. Works for my utorrent so I assume it’ll work for kaillera. 27886 that is.

Nothing is showing up for hosting or a waiting list. Wtf? Is there some way to verify if I’m connected to the p2p or to tell if my port is forwarded?

All waiting games made public should show up here:
It will appear on someone’s p2p client list if and only if they can ping you.

Well, if you are having connection problems despite port forwarding, there are 2 things to look out for. Can you connect via the waiting games list and can you connect directly using your external IP. If you can connect via waiting games list and not with IP directly, you are fine…just connect via waiting games list. If you can connect with IP and not via waiting games list, something can be done about it. But if you cant connect either way, you’re better off sticking to hamachi for breakfast.

an important thing to remember is, if you happen to DHCP your local router, then be aware that during any reset, your local IP may change. even though your port might be forwarded on, your local IP might be .1.101 instead (this is all assuming you have more than 1 computer using your router) – i know that often i reset my router and forget to double-check my IP.

this could also be a cue to assign IPs to each computer for easier identification down the line ;p (note to self anyway)

Alright, well A game finally showed up on my waiting list. Now trying to host a game. I don’t have anyone’s IP to connect to. Maybe I’m just not getting anyone because there are far less people using p2p than the actual client.

Edit: someone just hooked up on my hosted game but left so I am getting connections, it’s just that there aren’t as many people as on the client.

Can anyone tell me what this error means?