Google Voice is Google's interface into the PSTN (Public Switched Telephone Network), i.e. traditional telephony. You access the web interface for Google Voice at www.google.com/voice. Google gives you a free PSTN telephone number. Calls to this number can be configured to go to any of your other phone numbers, e.g. cell phone, home number, office number, or to your Google Talk account.

The web interface to Google Voice is over SSL (TCP/443). To block access to this interface, you must enable SonicWALL DPI-SSL CI (Deep Packet Inspection Secure Sockets Layer Client Inspection) and this signature.

This SonicWALL signature blocks access to Google Voice web interface over SSL (TCP/443) only when DPI-SSL CI is enabled.