NAT Problems – And a Big Opportunity For Online Multiplayer Games

Today I had planned to do something else what I ended up doing: I spent whole day figuring out how to deal with the NAT problems (big thanks for Tim for helping me out so far). So far I understand in theory what should be done: we need an introducer.

NAT problems occur when both (I think) the server and client are behind a router/firewall that messes up the IP addresses and ports. And that means players cannot play the game. It’s like a mailman who tries to deliver a package to John Doe, when suddenly he realizes that John moved to somewhere.

There are good resources that have shed some light into this issue. Here are some of them:

Something good in this adversity
There’s something good in this crappy situation. Big studios also have this problem – and so does every online multiplayer game (excluding games that have servers with public IPs, such as most MMO games). You can also see that not everybody is willing to deal with this problem (even world’s largest gaming companies such as EA might not be willing to make it work 100% properly).

And since it’s a big problem (and something not everybody is even going to solve) it means an opportunity. It means that those who make playing smooth and tackle NAT problems will get access to larger player pool. We are definitely working on this problem, and finding a solution for it.

I’m open to ideas and suggestions in this matter – even willing to pay some $$$ for somebody to solve this problem. We need to get an application that can be run on an external server: something that will make sure our UDP traffic goes where it should. If you have an idea, feel free to contact me.

Juuso Hietalahti


  1. Not being a technical specialist in any way I just wanted to pipe in that NAT is spawned by the devil and I applaud any efforts to sidetrack it. It appears Dawnspire works fine with NAT:s when playing. But when trying to put up a server it’s pure hell and I don’t know if any of our fans have successfully found a solution on their end. >_

  2. It’s a huge issue… one we are currently spending a lot of time on and will have lots to say about publicly real soon now. You can get the gist of our solution here

    hint: jabber/xmpp/jingle rules!

  3. One good thing to start with is to clarify exactly what the problem is. I think you are referring to the problem of a person hosting his/her own server for multiplayer gaming only to find that no one else can connect to the server. As far as the host is concerned, the machine has network access. It’s just that no one else can connect to the game.

    The server probably has an IP address in the range of 192.168.*.* or 10.1.*.*. Those are internal, local network address ranges. If someone tries to connect to an IP of, then either they have their own local network and can connect to the address (if it exists), or they won’t be able to connect at all since no public address is available in that range.

    I recently had this problem with Diablo 2 hosting as well as Pioneers, an open source Settlers of Catan clone. Pioneers was easy enough to figure out but required manually entering an IP address. Diablo 2 required that I opened specific ports on my router. Neither way is very friendly to people who don’t want to fiddle with communication equipment just to play a game.

    I think I recall Blizzard sticking its head in the sand at one point. If you wanted to play with multiple people on Battle.net in the same room and you had a switch, tough luck. I’m sure that problem has been resolved though. Still, it is surprising that so many big names were ignoring network problems by claiming that they didn’t support hubs/routers/switches. It’s the reality of the customer’s network! Deal with it!

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