Iptable: the best configuration?

Hello
now i finished to install asterisk and freepbx on my cloud space.
In this moment iptables are all disabled, because in the guide is write launch the command :“chkconfig --level 0123456 iptables off”

I have to enable some level?
This is the guide i follow
http://wiki.freepbx.org/display/FOP/Installing+FreePBX+12+on+CentOS+6.5

Thank you