Which of the following is true regarding QoS and bandwidth?

• A. QoS allows you to control bandwidth.
• B. QoS can automatically negotiate VPN tunnels.
• C. QoS can decrypt TLS sessions.
• D. QoS can disable NICs on hosts.

Answer: (A)

Quality of Service centers on controlling how bandwidth is allocated among different traffic streams. By classifying and prioritizing traffic, QoS lets a network reserve bandwidth for important applications or cap less critical ones, ensuring smoother performance when the link is congested. That makes the statement about controlling bandwidth the correct one. QoS does not automatically negotiate VPN tunnels; VPN setup and tunnel negotiation are handled by VPN protocols and devices, not QoS. It also does not decrypt TLS sessions—TLS encryption is end-to-end and decryption would be a separate function, not part of QoS. And QoS does not disable NICs on hosts; it manages how data is queued and transmitted, not device operation. In practice, you might mark packets with DSCP values and shape or police traffic to enforce the priorities you need.