Multiple choice

Which of the following statements describes the use of voice VLANs in Cisco IP telephony?

  1. The voice VLAN carries both tagged and untagged traffic.

  2. The voice VLAN carries untagged traffic having special QoS markings.

  3. The voice VLAN must be configured on the switch port to which the IP phone attaches.

  4. Data and voice frames are tagged with same VLAN ID between the IP phone and the switch when a voice VLAN is configured.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In Cisco IP telephony, voice VLANs must be configured on the switch port connected to the IP phone. The IP phone tags voice traffic with the voice VLAN ID while data traffic passes through untagged or with a data VLAN. Option A is wrong because voice VLAN carries only tagged voice traffic. Option B is wrong because voice VLAN carries tagged traffic, not untagged. Option D is wrong because voice and data use different VLAN IDs. Option C correctly states that the voice VLAN must be configured on the switch port.

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