Ethernet ports (using an RJ-45 connector) are very common and less expensive than specialized serial ports and associated cables. Service providers can offer an Ethernet interface to their customers for their WAN connectivity. The service provider configures the logical connections (in the provider network) required to connect the customer to sites. The technology used in the provider’s network is hidden from the customer, allowing what appears to be Ethernet connectivity to each of the customer sites. Actual throughput between sites is controlled by the provider based on the level of service purchased by the customer. Metro-Ethernet is certainly exciting when you consider the speeds possible and the use of such a familiar technology!