CompTIA Network+ Practice Test

What should be the configuration for voice VLANs when integrating VoIP?

1. Voice VLAN should share the same IDs as data VLANs

2. Every switch interface must have both a data VLAN and a voice VLAN

3. All traffic must be untagged to ensure compatibility

4. Only the phone can be on a VLAN, the computer must not be connected

The correct answer is: Every switch interface must have both a data VLAN and a voice VLAN

When integrating Voice over Internet Protocol (VoIP) with a voice VLAN configuration, it's essential for every switch interface to have both a data VLAN and a voice VLAN. This approach allows for the separation of voice traffic from data traffic, which is crucial for maintaining quality of service (QoS) for voice communications. Voice traffic is often sensitive to latency and delays, so having a dedicated VLAN helps to prioritize and manage this traffic effectively. By configuring both a data and voice VLAN on each interface, network devices can properly identify and handle the types of traffic being transmitted. The voice VLAN can be specifically configured to provide better performance for VoIP applications, such as prioritizing voice packets over standard data packets. This setup can enhance call quality, reduce jitter, and improve overall network performance. In contrast, the other options suggest either overlapping VLAN IDs, untagged traffic configurations, or restrictions on devices that would not promote the optimal handling of VoIP traffic. Sharing VLAN IDs would lead to congestion and inefficiency, untagged traffic could create compatibility issues, and limiting the phone's VLAN access would unnecessarily complicate the network setup. Thus, the recommended configuration supports a clear and effective separation of voice and data traffic, maximizing performance and reliability in VoIP systems.