Which network connection has a relatively high cost, billed on a per port charge and per mile for the length of the circuit?

Leased lines are indeed characterized by a relatively high cost due to their pricing structure, which typically includes charges based on the number of ports and the distance (measured in miles) that the line covers. This pricing model reflects the dedicated nature of leased lines, which provide a continuous connection between two points and are not shared with other users.

The cost factors in leased lines are influenced by the installation, maintenance, and operational expenses incurred by service providers. Since these lines offer guaranteed bandwidth and reliability, they are often preferred for businesses that require consistent connectivity for critical applications. Their dedicated nature also means that they can support higher data rates without the variability often experienced in more shared or consumer-focused services, justifying the higher costs associated with their deployment.

In comparison, other types of connections, like dial-up and cable modems, are generally lower in cost and do not follow a pricing model based on per-mile charges. Dedicated circuits, while they can have costs associated with them, typically refer to specific technologies or arrangements rather than the broad category of leased lines which includes those key billing characteristics.