There is nothing for bandwidth control prior to RU5. RU5 now offers an apache module to control bandwidth. See the "What's New" notes here:
What's new in Symantec Endpoint Protection 12.1.5
Bandwidth control for client communication
The management server now includes an Apache module that you can configure to control network bandwidth. The module reduces the network load between Symantec Endpoint Protection Manager and the client computers, especially when the clients download content definitions or client installation packages.
Although, no further info has come out on it...probably need to contact support.