Here are descriptions of the more relevant changes in EVSS 3.1
Added compatibility with RFC 6188: audio data can be encrypted with AES-128 or AES-256, depending on endpoints:
A new icon in notification bar constantly inform use if PrivateGSM is currently connected to PrivateServer and ready to receive secure calls.
Data archival is about archiving automatically historical data on file system and removing them from SQL database. Administrator can configure the time window to keep historical data online. Archived data can be exported/downloaded and removed from PrivateServer.
This version introduces data archival for SIP Sessions data, which are generally useful only for debugging and support purposes.