Final answer:
When a Voice VLAN is set up, Quality of Service (QoS) is enabled by default to prioritize voice traffic, but Voice over IP (VoIP) is not disabled when the Voice VLAN is removed, requiring manual adjustment of QoS settings.
Step-by-step explanation:
When a Voice VLAN is configured, Quality of Service (QoS) is automatically enabled; however, Voice over IP (VoIP) is not automatically disabled when that same voice VLAN is disabled. This configuration is important to ensure that voice traffic is prioritized over other types of network traffic, which is essential for maintaining the quality of VoIP communications. Even when the Voice VLAN is no longer active, administrators might need to manually adjust QoS settings to reflect the change in network configuration if those settings are no longer required for other services.