An administrator has recently moved all VoIP to a CaaS offering. In order to ensure that VoIP traffic remains separate from the rest of the data traffic, which of the following MUST be done?

VLAN tagging allows for the logical segmentation of a network, enabling different types of traffic, such as VoIP, to be isolated on separate virtual networks even when sharing the same physical infrastructure. This ensures separation and can help prioritize critical traffic.

Creating a new subnet alone does not guarantee traffic separation at the data link layer unless specific routing and firewall rules are also implemented; VLANs directly address layer 2 separation.

A private VPN establishes a secure tunnel but is not primarily used for basic traffic separation within an existing local or cloud network segment; it's for secure remote access or site-to-site connectivity.

QoS (Quality of Service) prioritizes traffic but does not separate it into distinct logical networks; its purpose is to manage bandwidth and latency, not isolation.