I think I am unable to have my php application get access to the network. The error reported is in the above link.
What the solution proposed in http://www.linuxforums.org/forum/red-hat-fedora-linux/46840-fsockopen-error-13-permission-denied.html is:
The firewall is enabled on my server: policy type is targeted, enforcing current is checked and HTTPD scripts to connect to the network were not allowed.
Where: Desktop > System Settings > Security Level > SELinux > httpd > HTTPD scripts to connect to the network was unchecked. I checked it and it is working now.
How can I change httpd.conf to do the above?