VPN / Remote Access
Some times a company has more than one office that needs to be networked over great distances. This is achieved using high speed data lines and creating Virtual Private Networks that are routed over these connections. An emerging trend is for a company to provide a VPN access tunnel to their remote or traveling employees so they can access the corporate network.
In short, Virtual Private Network typically uses the Internet to connect remote sites or users together. Instead of using a dedicated site to site connections, a VPN uses "virtual" connections routed through the Internet. This method allows an employee to work while traveling or from home.
Through the use of dedicated equipment and large-scale encryption, a company can connect multiple fixed sites over a public network such as the Internet. Site-to-site VPNs can be one of two types:
Intranet-based: If a company has one or more remote locations that they wish to join in a single private network, they can create an intranet VPN to connect LAN to LAN.
Extranet-based: When a company has a close relationship with another company (for example, a partner, supplier or customer), they can build an extranet VPN that connects LAN to LAN, and that allows all of the various companies to work in a shared environment.