Final answer:
A VPN Concentrator is a device designed to manage encrypted connections over an untrusted network like the Internet, different from firewalls, routers, and switches which have other primary functions.
Step-by-step explanation:
The dedicated device designed to manage encrypted connections established over an untrusted network such as the Internet is a VPN Concentrator. A VPN Concentrator is a type of networking device that provides secure creation of VPN connections and delivery of messages between VPN nodes. It is used in businesses and large organizations to aggregate hundreds to thousands of VPN tunnels. Unlike firewalls, which protect the boundaries of a network, or routers and switches, which manage traffic within networks or provide connections to different networks, a VPN Concentrator is specifically focused on creating and managing VPN communications.