With the growing popularity of the Internet, Virtual Private Networks (VPN) have gained acceptance as a way for companies to communicate with each other,with their distant offices or with employees working remote.
Expected to replace the traditional Wide Area Networks (WAN), VPNs have today become popular and for many in the West synonymous with using the Net.
WANs typically used ISDN or optic fibre lines through which companies expanded their network beyond their immediate geographical area. This was reliable and secure, but was expensive because of the physical costs involved, particularly if offices and employees were in distant areas. VPNs became a low-cost alternative to WAN. By using the intermediate network of the Internet, it saves costs on long-distance phone service and hardware costs associated with dial-up or leased lines.
VPN is a shared network where private data is segmented from other traffic on the Net, which only the intended recipient can access. Supposing Joe is an employee who is working from a remote city in Tamil Nadu, he can log on to his Chennai office's Local Area Network (LAN) from his laptop using VPN. The data that he sends to his company is encrypted and secure.
In a typical VPN deployment, a client initiates a virtual point-to-point connection to a remote access server over the Internet. The remote
access server answers the call and tranfers data from the VPN client to the organisation's LAN after authenticating the client. VPN connections can also be between two office sites linking two portions of a private network.
Three of the properties of VPNs - encapsulation, authentication and data encryption - are worth remembering. VPN technology provides a way for data to be encapsulated with a header that allows data to traverse the Internet.
Authentication could be either in the form of digital certificates or the usual user name-password format. Encryption is when data is coded so that only the intended recipient computer can crack it. For example, let's say that the code is A is C and B is D and so on and only the sender and recipient are privy to the code, then the encryption is successful.
Another aspect of VPNs are the protocols that they use. Point-to-point Tunneling Protocol (PPTP), the most popular one, is heavily reliant on the older and popular Point-to-Point Protocol (PPP) designed for dial up and dedicated Internet connections.
In India, companies like Airtel and Reliance offer VPN service to their clients. Airtel offers VPN connections with a bandwidth between 2 MBPS to 155 MBPS to many of its clients that include software firms and banks.
Reliance offers a carrier-grade, MPLS-based VPN service in 172 points-of-presence (PoP) of bandwidth that can be anywhere between 64 KBPS to 1 GBPS. ``In the last six months, over 100 customers that include many multi-national companies have chosen Reliance for their mission-critical tasks. They have even preferred our service to those in countries they are based in,'' a Reliance spokesperson said.
He also asserted that in situations where offices from multiple locations have to be connected, VPNs are at least 20 percent cheaper than leased lines.''
Both Reliance and Airtel offer service level agreement-based services to their clients. The service provided is end-to-end, which means that companies with the dough can actually avoid the infamous last-mile restriction. If Joe has a laptop and a mobile phone, he can use his
company's VPN service to send data over a secure line instead of just using the unreliable, insecure medium of the Internet. And that is the allure of VPN, which companies and remote employees are falling for.