Hi Marcos Tito,
You should be able to use SharedView without having to open any ports.
And there was a thread about firewall configuration at
http://forums.microsoft.com/sharedviewbeta/showpost.aspx?postid=1593303&siteid=59&sb=0&d=1&at=7&ft=11&tf=0&pageid=0
If you are experiencing similar issue as user KAKueh and Chris Brush, please try the recommend steps Maria Hristova suggested and see if it solves the problem.
Please let us know if this solves the problem you’re experiencing.
Thanks,
Tony Lee