RDL-3000
FAMILY
USER MANUAL
70-00158-03-00
Proprietary Redline Communications © 2015
Page
158
of 254
April 17, 2015
VLAN (802.1Q) Field Definitions
The tag is located at the position used for the EtherType/Size field in untagged frames.
Table 30
:
Diag. - 802.1Q Tag Field
16 bits
3 bits
1 bit
12 bits
TPID
PCP
CFI
VID
Tag Protocol Identifier (TPID)
: 16-bit field set to 0x8100 identifies the IEEE 802.1Q-
tagged frame. Located at the EtherType/Size field position (untagged frame).
Priority Code Point (PCP)
: 3-bit field IEEE 802.1p priority bits from 0 (lowest) to 7
(highest).
Canonical Format Indicator (CFI)
: 1-bit field. Value 0 indicates MAC address is in the
standard format for Ethernet switches.
VLAN Identifier (VID)
: 12-bit field specifying the VLAN. The VLAN value may be 1 to
4094. Value 0 indicates the 802.1Q tag is specifying only a priority
.