CertExams.com Simulator Lab Exercises Answers

Configuring voice VLAN

Description: Lab exercise explains configuration of voice VLAN.

A voice VLAN is a VLAN ( virtual local area network) that is specifically allocated for user's voice data streams. It ensures the quality of voice traffic by improving the transmission priority of it when transmitted with other traffic. That is to say, when other services (data, video, etc.) are transmitted simultaneously, voice service will be prioritized and transmitted with a higher forwarding priority. The voice VLAN feature is used to prioritize the transmission of voice traffic. Voice traffic is typically more time-sensitive than data traffic, and the voice quality can deteriorate a lot because of packet loss and delay. To ensure the high voice quality, you can configure the voice VLAN and set priority for voice traffic. A voice VLAN can operate in two modes: manual mode and automatic mode.

Manual mode: This mode is applicable when the switch port forwards voice traffic only. You manually add ports connecting IP phones to the voice VLAN; then the switch will apply priority rules to ensure the high priority of voice traffic.

Automatic mode: This mode is applicable when voice traffic and data traffic are transmitted on the same switch port. When a port receives a voice packet, the switch automatically adds the port to the voice VLAN and applies priority rules. The switch forwards voice traffic in the voice VLAN and data traffic in other VLANs.


1. Enter into configuration mode

2. Create two vlans 10 and 20

3. Configure interface fa0/1 in access mode

4. Configure vlan 10 as data vlan

Note: Please refer to the CertExams.com Network Simulator software for complete lab with commands.

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