About Virtual Area Network and Virtual Private Network
– There are users who are located in proximity with each other or are quite dispersed.
How are they to be connected?
– Their problem is solved through a VAN or virtual area network.
– This type of computer network provides a high bandwidth connection to such users.
– This connection is built up on the cable modems, ADSL lines and other similar high bandwidth networking technologies.
– A virtual area network supports the following:
1. Social interactions
2. Medical communications
3. Legal consultations and so on.
– In some situations it is required to extend the private networks as well as resources.
– These are the resources that are contained in the network that stretches across public networks.
– A network used for extending such networks is called the virtual private network or VPN.
– With the virtual private network, a host computer can receive or send data across various networks whether they are public or shared.
– The whole network functions as if it were a private network possessing all the security and management policies and functionality that usually belong to a private network.
– Such a connection can be established via a virtual point – to – point connection that is in turn established via encryption and dedicated connections.
– The biggest example of a VPN is the VPN connection that stretches across the internet.
– It actually happens to be a wide area network (WAN) even though it appears to be a private network link to the users.
– This is why this network type has been named as the virtual private network.
– The data networks that were used earlier used leased line connections or dial – up modems for establishing VPN – style remote connectivity.
– They often utilized ATM (asynchronous transfer mode) virtual circuits and frame relay for making these connections. – These circuits were owned by telecommunication carriers such as Verizon, AT&T etc.
– However, one cannot consider these networks to be of true VPN types since the data transmitted is passively secured by creating some logical data streams.
– Such networks have paved way for VPNS based on IP and MPLS (multi-protocol label switching) as they have helped in making significant reductions in the cost and rise in the bandwidths that have been introduced by new technologies like fiber optic networks, DSL (digital subscriber line) and so on.
Types of Virtual Private Networks
Virtual private networks are of two types namely:
1. Remote – access VPN: This type connects an individual system to the main network.
2. Site – to – site VPN: This type establishes a connection between the two networks.
– Usually in corporate areas the first type VPNs are used since using they provide the employees with the access to the intranet of their company from no matter where they are i.e., either at home or while travelling.
– On the other hand, with the second type of VPN a cohesive virtual network can be shared by the employees whose offices are situated at different geographical areas.
– A VPN might be used for interconnecting two similar networks over a dissimilar one.
– VPN networks can be classified based up on the following:
1. Protocols used for tunneling the traffic
2. The termination point of the tunnel
3. Type of connectivity offered
4. Security levels provided
5. OSI layer
The security mechanism of VPNs provides:
1. Message integrity: for the detection of any tampered transmitted messages.
2. Sender authentication: for keeping the unauthorized users at bay from using the VPN.
3. Confidentiality: for saving the data from being sniffed.
The following constitute a secure VPN protocol:
– Internet protocol security (IPSec)
– SSL/TLS (transport layer security)
– DTLS (datagram transport layer security)
– MPPE (Microsoft point – to – point encryption)
– SSTP (secure socket tunneling protocol)
– Multi path VPN (MPVPN)
– SSH (secure shell) VPN
Tunnel endpoints need to be authenticated for securing the VPN tunnels. Remote access VPNs might be created by users such as biometrics, passwords or two – factor authentication.