I would recommend an upgrade from AOS 3.3.3.7
This code is no longer supported by Aruba Networks - please see EOS notice at;
http://www.arubanetworks.com/support-services/end-of-life-products#ArubaOSSoftware
Now on the good news front you have PEF license, in AOS 3.4 the VOC license was rolled into the PEF license.
Now after upgrading from 3.x to 5.x the PEF license is automatically updated to the PEFNG license so you have no need to buy any further licenses.
From 5.x release notes;
Licensing Change History
The following changes and/or consolidations were made to the ArubaOS licensing.
ArubaOS 5.0
MAP was merged into base ArubaOS
VPN was merged into base ArubaOS
RAP was merged into AP license
PEF (user basis) was converted to PEFNG (AP basis) with ArubaOS 5.0
ArubaOS 3.4.1
VOC was merged into PEF. This merge happened with ArubaOS 3.4.1
MP was merged into base ArubaOS
ArubaOS 3.4.0
ESI was merged into PEF
I would recommend an upgrade to the latest AOS 6.1