devices that are separated by a broader geographical area. the services of carriers, such as telephone companies, network providers serial VPN is an encrypted connection between private networks over a public network such as the Internet. Instead of using a dedicated Layer 2 connection such as a leased line, a VPN uses virtual connections called VPN tunnels, which are routed through the Internet from the private network of the company to the remote site or employee Ethernet is a rapidly maturing networking technology that broadens Ethernet to the public networks run by telecommunications companies. •IP-aware Ethernet switches enable.