An IEEE standard for providing VLAN identification and quality of service (QoS) levels. Four bytes are added to an Ethernet frame, increasing the maximum frame size from 1518 to 1522 bytes. Three bits are used to allow eight priority levels (QoS) and 12 bits are used to identify up to 4096 VLANs. See virtual LAN.
The IEEE specification that defines a virtual LAN (VLAN), which allows multiple logical LANs to share the same physical infrastructure. 802.1q defines a 32-bit tag that is added to the frame header to identify the specific VLAN and provide for priority indication. See also frame, IEEE, header, LAN, logical, physical, and VLAN.