Specify ports - if you are able to host it would be best to choose this option.
Once you connect to the matchmaking server you will be greeted with this waiting screen. Unless it's an active time in Japan, there will usually be nobody else on the server. Match statistics are maintained and tied to player ids. These will be displayed under the player information at the character select screen. After a match is completed through this service both players return here. This can be somewhat troublesome since you have to wait up to thirty seconds before connecting with somebody again, provided they are still there.