If you are having bandwidth
limitations the best solution is use GUPs for updating clients
Fore more information
regarding GUP refer the below doc
http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2007092720522748
If you are using RU 5 a lot
of new features are available. For details refer the below doc
http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2009092901593448