You have to SSID swap for this game whatever your Psp/Operating System/Firmware/adapter/Dissidia's version/umd/iso could be.
To make it short, here is how it works:
I-You invite or get invited by someone to play; you confirm it.
II-While the connection is preparing, you get into your SSID's window(the same which let you connect to the lobby0); you refresh it.
III-You connect to the SSID which appeared. It should be a crazy combo of numbers and letters, representing your opponent's Mac address.
To make this process more comfortable, it is possible to let your adapter do the job for you by applying the second method.
May you find screened guides below.
First method: SSID swapping manually.
As you can see it, Windows configuration tool was used for this tutorial but it remains universal: just replace the windows by the ones of your own utility.
You should now start to see people appearing in the online lobby. If you see nobody, refresh the previous “Lobby0” SSID by disconnecting right before connecting again.
Invite someone by clicking on his card and selecting the first option.
This is the crucial part.
Get back to your SSID window(the one you used to connect to the lobby) and hit F5 to refresh: you shall see a new SSID composed by a crazy combo of letters and numbers. Refresh as often as necessary if you do not see the new SSID appearing yet. Connect to it.
You are connected.
Second method: Making SSID Swap automatical.
Note about Planex users.
If you are using a Planex for Kai and its utility to get SSIDs then you are in luck: this configuration makes SSID swapping automatical as long as the “follow Psp SSID” option is enabled in your configuration.
However, if you are using any other adapter, you can still make the swap automatical by applying the following.
Do not be disrupted by the interface: this method works with all operating systems. Just find the equivalents. The Windows 98's had been chosen because it is the most light and the clearest among all.
Load up Network Connections from your Control Panel.
Let Windows configure your wireless network settings.
Now, click on “Wireless Networks” tab then Select “Advanced”.
Set it up as above.
Now get into Cornéria, open your SSID's window by double clicking on your adapter's icon in the tool bar and connect to the “Psp_…_LobbyO” SSID by double clicking on it as well. Invite someone or let yourself invited: the SSID swap occurs while the “preparing connection” screen is displayed.
Using this method, Windows could encounter problems to get back to the lobby if a previous swap was missed. To solve this problem, just refresh your SSID window and see Windows connect you back to the lobby0.
Note about the “WoL glitch”: if you cannot see your opponent changing his character and his selection looks like to be stuck on a Wol level one, then it is due to a desynchronization. Just get back to the lobby and try to link to your opponent once again. If it fails, rekai.
Here are some tips to reduce your lag.