I have had this one in the queue for a while (I don’t even run of Fedora 20 anymore).  This one will be short and sweet, because there really isn’t a bunch of discussion that needs to go into it.

By default Fedora 20 will block outbound PPTP VPN connections.

bash 
firewall-cmd --direct --add-rule ipv4 filter INPUT 0 -p gre -j ACCEPT
firewall-cmd --direct --add-rule ipv6 filter INPUT 0 -p gre -j ACCEPT

Reload the rules.

bash 
firewall-cmd --reload