Hello,
Check this Article:
Can Symantec AntiVirus or Symantec Endpoint Protection clients be managed through a VPN?
http://www.symantec.com/docs/TECH100120
Just to confirm, you are talking about Symantec AntiVirus 10.x, correct?
If yes, then on a Kind note: Symantec AntiVirus 10.x is a End of Support Life product.
It recommended to Migrate Symantec AntiVirus 10.x to Symantec Endpoint Protection 12.1
On July 4, 2012, Symantec AntiVirus (SAV) 10.x and Symantec Client Security (SCS) 3.x will reach End of Support Life (EOSL). This includes all maintenance packs and patches.
End of Life announcement for Symantec AntiVirus Corporate Edition and Symantec Client Security
http://www.symantec.com/docs/TECH178551
Frequently asked questions about Symantec AntiVirus 10.x End of Support Life
http://www.symantec.com/docs/TECH184999
Hope that helps!!