"This is a kaillera server" ~ Agent 21 iXi

What is Kaillera?
Kaillera is a client/server system that enables net-play for game system emulators. Kaillera does not provide the emulator itself, or the ROM files to emulate. Kaillera simply plugs into any emulator and maps, for example, player 2's input to another user (player 1) via UDP network communication.
What is EmuLinker?
EmuLinker is an improved Kaillera network server. EmuLinker's purpose was to completely rewrite the original Kaillera network server architecture for the sole purpose of preventing exploitable bugs, improving optimization/performance and adding features. EmuLinker was developed by Moosehead/MonospaceSoftware/Paul Cowan.
Which Kaillera Client is better?
All of them are incomplete and have some flaws. The most popular is Open Kaillera - n02 v0.5r1 (1 nov 2007) - which contains stable synchronization but has some other bugs, errors, and poor optimization.

SupraClient and Slink Client also have stable synchronization. New versions of these clients are now stable, implement bug fixes, improve optimization/performance, implement additional features and additional security measures.

We do not recommended using the n02 Kaillera client that came out around 2010-2011, also known as OwnaClient (modified version of Open Kaillera n02 - based on older version v0.5r0 (6 sep 2007)); it has new options but it's the most unstable and has frequent desync.
What is desync?
Desync is when 2 or more player's emulators get out of sync while communicating to each other via Kaillera Client-to-Server, so what you're pressing is not what the other person is seeing. It's a big and rare unavoidable issue with Kaillera, since making an emulator play over the Internet via client-server architecture is not what it was originally intended to do. A fast and stable Internet connection for all players is the best way to avoid desync.

You can spot desync when your opponent stops moving suddenly, or start moving eratically without purpose. EmuLinker servers can also detect some forms of desync and will print a notification in your game room. The best thing to do is quit the game and restart it back up.
What is lag? What is delay? Why is my ping so high?
People tend to confuse the two, but simply, lag and delay are not the same thing.

Lag occurs when one player experiences Internet congestion or computer problems, and stops transmitting network packets to the Kaillera server. This causes the other player's games to freeze momentarily until the lagged person recovers. If the lagged person does not recover promptly, desync will occur.

Delay occurs when one or more players are using a slow or busy Internet connection, or they are too far from the server in the physical aspect. Delay does not cause freezing, but the game will seem slow and jittery for all players in-game. Delay is directly related to ping time for each individual user. Desync can most likely occur when playing with a severely delayed person.

Ping time is usually related to network speed, network congestion, connection, and physical location from the server itself. Therefore, a high ping indicates:
  • Your network connection is too busy. Stop all downloads, file sharing programs, etc. Or seek out a faster, better Internet plan.
  • The server's network connection is too busy (bandwidth may be exceeded). There is nothing you can really do in this case. The server administrator should reduce the number of allowed users or purchase a better server plan.
  • Your are too far away from the server in the physical aspect. The closer you are to the server physically, the less distance your network packets will have travel, thus the faster your connection will be. If you're having issues, try seeking a closer server to you.