The servers for PES online are normally closed after a certain period. The last ones to be closed were those for PES 2011 in January 2013.
Any information such as this will be posted on the official website http://www.konami.jp/we/online/ and other official PES web and social pages.
We are sorry about any inconveniences this may experience, however, we would like to suggest you try the currently available online modes of PES 2012 and PES 2013 for more fun!