[N7700] Too much time for getting a remote connection to Mysql

Hi !

I have a N7700PRO and I've installed the MySQL5 module from thecus website.
I've written an application in Java and I'm using the mysql driver for java (mysql connector/J) from mysql and since yesterday it takes me about 20 secondes for establishing a connection with my database !

I've tried with others tools (and others drivers) to have a remote connection and it's the same problem : establishing a connection take too much time.

Yesterday we have reboot the nas and we havse seen something like "Download driver...", can it be responsible ?

Thanks a lot for your help !