****************************************
* Description: Knowledge of network VPN
* Compatiablity: RDBMS 11g, 12c
* Date: 05:25 PM EST, 05/11/2017
****************************************


 
<1> Virtual Private Network [VPN]:
     |
     |__ 1) A VPN utilizes public telecommunications networks to conduct private data communications. Most VPN implementations use the Internet as the public infrastructure and 
            a variety of specialized protocols to support private communications through the Internet.
            VPN follows a client and server approach. VPN clients authenticate users, encrypt data, and otherwise manage sessions with VPN servers utilizing a technique called tunneling.
         
		 
         2) VPN clients and VPN servers are typically used in these three scenarios:
             o. Support remote access to an intranet,
             o. Support connections between multiple intranets within the same organization, and
             o. Join networks between two organizations, forming an extranet.
		
		
         3) VPN is a Client/Server [CS] structure based. Currently, popular VPN client softwares are:
             o. Cisco Anyconnect Secure Mobility
             o. Cisco Systems VPN
             o. GlobalProtect
             o. OpenVPN
             o. Check point Endpoint Security
             o. FortiClient
             o. Windows VPN
             o. HID Global
             o. Sophos VPN
             o. SonicWall