Hello,
Symantec Insight for Private Clouds appliance
Symantec Insight for Private Clouds Endpoint Edition is typically installed in networks without Internet connectivity. The private server stores a copy of Symantec Insight's reputation database in your private cloud. Symantec Endpoint Protection reputation queries are HTTP or HTTPS requests to the private server rather than to Symantec's Insight server.
The private server downloads the Symantec Insight data over an encrypted, secure connection. You can manually update the Insight data or use third-party tools to check for updates and download the data automatically. Your update method depends on your network and the type of server on which you run Symantec Insight for Private Clouds.
When you use a private Insight server, Symantec does not receive any queries or submissions for file reputation.
Check this Article:
What's new with Latest Symantec Endpoint Protection SEP 12.1.RU3
https://www-secure.symantec.com/connect/blogs/whats-new-latest-symantec-endpoint-protection-sep-121ru3
Hope that helps!!