VPNs and Their Benefits

A VPN is an encrypted connection between private networks over a public network such as the Internet. The V stands for virtual, and the N stands for network. It is a technology that allows users on different switch ports to participate in their own network separate from, but still connected to, the other stations on the same or connected switch. The information from a private network is securely transported over a public network, the Internet, to form a virtual network. The P stands for private. To remain private, the traffic is encrypted to keep the data confidential. Virtual LANs are primarily a feature of network switches. Because most true hubs cannot perform segmentation based on MAC addresses, they cannot do VLANs. Although NICs are required in order to use a VLAN, VLANs are not a primary feature of them. Instead of using a dedicated Layer 2 connection such as a leased line, a VPN uses IPsec to form virtual connections that are routed through the Internet from the private network of the company to the remote site or employee host.
Benefits of VPNs include the following:
■ Cost savings: VPNs enable organizations to use cost-effective third-party Internet
transport to connect remote offices and remote users to the main corporate site, thus
eliminating expensive dedicated WAN links and modem banks. Furthermore, with the
advent of cost-effective high-bandwidth technologies, such as DSL, organizations can
use VPNs to reduce their connectivity costs while simultaneously increasing remote
connection bandwidth.
■ Security:VPNs provide the highest level of security by using advanced encryption and
authentication protocols that protect data from unauthorized access.
■ Scalability: VPNs enable corporations to use the Internet infrastructure within ISPs
and devices, which makes it easy to add new users. Therefore, corporations are able to
add large amounts of capacity without adding significant infrastructure.
■ Compatibility with broadband technology: VPNs allow mobile workers, telecommuters, and people who want to extend their work day to take advantage of high-speed, broadband connectivity, such as DSL and cable, to gain access to their corporate networks, providing workers significant flexibility and efficiency. Furthermore, high-speed broadband connections provide a cost-effective solution for connecting remote offices.