Which of the following is NOT a primary service provided by a VPN concentrator?

A VPN concentrator primarily focuses on creating, managing, and securing VPN connections. Its key services include establishing VPN tunnels, handling authentication processes, and managing accounting services related to user sessions and activities within the VPN network.

Providing customer service, while essential for any business offering technological solutions, does not fall under the primary functions of a VPN concentrator. The role of a VPN concentrator is more technical, centering around connectivity and security for remote users rather than direct customer engagement. Thus, the option regarding customer service stands out as not being aligned with the core responsibilities of a VPN concentrator.