Playing on Kai in optimal conditions.

Portforwarding.

Portforwarding's guide

By portforwarding, you will be able to connect with others every time with the best ping as possible shared with them. This is the main factor to play on Kai without any troubles. If you are a student in a campus or if you use any other public networks, you might not be able to play on Kai since you cannot access all those settings and configure them.

Preferring an Ethernet cable rather than a wifi card for your Internet's connection

Even if both work, a wireless signal is not steady and can be the cause of some lagspikes while you are playing. An Ethernet cable manages to broadcast the data flawlessly which means you will not have any.

Preferring Iso rather than Umd

Iso format works on Memory stick which exploits flash memory. That kind of data's transferring is the fastest in the world unlike the one of Psp's lens. If you are in official firmware, most of games isos are available in the Playstation Network. In the case you already got the Umd and do not want to pay twice for a same product, many games let you data install to increase the speed of data's writing; Dissidia and Tekken 6 are ones of them. Know that even if you data install, the quality of such data's writing remains inferior compared to the Iso's. If you are in custom firmware, you can easily rip your Umd to make an Iso. Make sure you have enough room on your Memory Stick: a clean Iso should be around 1.5 Go. Just change the “Usb device” to Umd(press select while in XMB to access this option under Gen firmwares), connect your Psp to your computer, explore it and move your fresh iso to whatever place in your harddrive. Now, change the Usb device back to Memory Stick and write your Iso on it.

Disabling all plugins(only for custom firmwares)

After many tests with various plugins, I can affirm the following without being able to explain it: plugins corrupt your Kai's connections somehow. Plugins which direclty affect the gameplay are the first concerned by this problem: Cwcheats, RemoteJoy… About Cwcheats, only codes which have been especially designed for Kai; like the one for Yugioh Gx Tag Force 4, will not cause you any trouble. Plugins which are not related to the ingame like Joysens will not cause you any trouble as well. Brief, if you want to save yourself from any headache, disable every plugins which belong to the first category.

Setting Cpu's Clock game to Normal Speed (only for custom firmwares)

If you set your Cpu's clock game to a higher or lower value, chances to get desync issues while playing someone are a little bit more important. Actually, Cpu's clock game had been reported as a problem in few cases but it still exists. Since few people think about changing the value of that setting, you really should let it to normal speed no matter what.

Monopolize your bandwidth for Kai as much as possible

Keep in mind the more your bandwidth is eaten, the more your lag gets important. That is why you should close any application(downloads/uploads, chat like WLM, browsing sites like Youtube) which eat it. It could be more problematic if others use your bandwidth at home as well: wife watching via TV via DSL's TV service, brother playing online on Ps3… There is a simple tip to lessen the impact of such a problem: enter the Mac address of every single device(computer's ethernet cable, Ps3's wifi card…) associated with its internal Ip (192.168.0.X) in your router's configuration (same page where you portforward).