how do i connect to nintendo wifi?

I have a dsi and wireless internet ive used on my ds but how can i connect to nintendo wifi?

It depends on if your router is compatable with your DSi

Because mine is not sadly

I find it very simple - i just turn on Wi-Fi connection on my DS lite and connect it with Wi-Fi router which I use for internet connection (I have 4 Mbit ADSL with simple Wi-Fi router). But, when I play Mortal Combat Ultimate it freezes and goes very slow. I don`t know if that is the problem with internet connection or game bug but it doesn`t work as it should be... M

OK, there is solution - it has something to do with Wi-Fi network security. If it`s open network - any kind of wireless network will work just fine, but if it`s locked with WEP or the other key, than it might not be compatible with Nintendo DS settings. So, keep your wireless network open, or choose security mode that fits your DS.