The American University in Cairo
School Of Business,Economics And Communication

1. What is a VPN?

2. Are there different types of VPN?

3. How does it work?

4. Are VPNs really secure?

5. Is a VPN the same thing as an extranet?

6. Then what is an extranet?


1.  What is a VPN?

VPN stands for Virtual Private Network.A VPN provides a secure way to access network resources over the Internet or other public or private networks and allows you to connect to a remote network and become a node on that network. VPNs use tunneling, encryption, authentication, and access control over a public network at the same time for security.Although they often use public networks, VPNs inherit the characteristics of a private network, thus the "Virtual" Private Network.A VPN can be a better alternative to traditional dial-up connections to provide access to remote users and telecommuters. It can also take the place of the public switched telephone network or dedicated leased lines to connect LANs in different sites. VPNs can also be used to give customers, clients and consultants access to corporate resources.

2.  Are there different types of VPN?

There are basically three types of VPN:

INTRANET: this type of VPN is usually implemented for commonly structured networks that may span various physical locations. An example would be a network that exists in several buildings connected to a data center or mainframe that has secure access through private lines. These may need strong encryption and strict performance and bandwidth requirements.

REMOTE ACCESS: Initiated by remote users to connect to their corporate LAN such as employees and telecommuters equipped with laptops that will connect intermittently from many different locations.

EXTRANET: This type of VPN uses the Internet as its base and deals with a wider scale of users and locations to allow customers and branch offices to access corporate resources across various network types.


3.  How does it work?

VPNs create "virtual" point-to-point connections using a technique called tunneling. As the name suggests, tunneling acts like a "pipe" which penetrates through a network to connect two points. Normally activated by remote users, tunneling encrypts data into standard TCP/IP packets and encapsulates it for safe transmission across the Internet.
VPN ensures the confidentiality and integrity of information as it travels over the public internet because it requires:

  • Remote user identity authentication
  • Secure private transmission of data (no unauthorized listeners
  • Verification of unadulterated data transmission

The VPN connection behaves like this:

  1. You connect to the Internet in the normal manner, through your ISP.
  2. The VPN client software on your computer initiates a connection with the VPN server.
  3. The VPN server encrypts the data on the connection so it cannot be read by others while it is in transit.
  4. The VPN server decrypts the data and passes it on to other servers and resources.


4.  Are VPNs really secure?

Any data packets that move across a publicly shared network like the Internet are potentially vulnerable to tampering. VPNs address that issue by employing multiple security mechanisms.But, what is safe enough? VPNs that employ multiple security systems, like additional hardware devices, software patches and security standards, can be considered secure. In most cases, security vulnerabilities will be introduced by the users, rather than the system.


5.  Is a VPN the same thing as an extranet?

No. Most VPNs can be designed to work as an extranet. But not all extranets are VPNs.


6.  Then what is an extranet?

Extranet is a general term than can mean many different things. The common definition of an extranet is a type of network that gives outside users, such as customers, clients and consultants, access to data residing on a corporation's network. Users access the data through a Web browser over the Internet and typically need to enter a user name and password before access to the data is granted.