i and my friend both having a psp..we want to play infrastructure mode together..but we cant..i try to host a game..his psp displayed the game no longer exist..but other ppl still can join my room and the slot isnt full..then i asked him to host again..he hosted and other ppl can join..only me cant join..
we're both from Malaysia..and playing trough psp..anyone can help us out here so that we can play online together?

[Edit] more option..
When we decide to join other ppl's room..for example A's room
when i join first..i can go in the Lobby..but he cant get in the Lobby..the message The game no longer exist displayed out..

then i quited the Lobby and came to the menu..then he can join A's Lobby again..
so weird all this thing happened..i cant play the game with him nicely..
it shows that we cant join the same room together in the same time..

Someone help?

are you sharing the same internet connection? if yes then probably more then 1 person with the same IP cant join a single game.

no..we're not sharing the same internet connection..just same region..different router..

Check your routers for the following:

Is UDP and TCP traffic on allowed ports 3074 and 3075?

Is UDP traffic allowed on ports 3076 to 3174 inclusive?

Does turning UPnP off on the router make a difference?

do we both need to do so for gaming purpose?

Yes, both of you.

but as i know that other people can join my friends lobby..he havent foward any port yet..why tis happened?