CTS HES-3109 Series - Page 61

61
IEEE 802.1Q VLAN Concepts
Introduction to 802.1Q frame format:
Preamble
SFD
DA
SA
Type/LEN
PAYLOAD
FCS
Original frame
Preamble
SFD
DA
SA
TAG
TCI/P/C/VID
Type/LEN
PAYLOAD
FCS
802.1q
frame
PRE Preamble
62 bits
Used to synchronize traffic
SFD Start Frame Delimiter
2 bits
Marks the beginning of the header
DA Destination Address
6 bytes
The MAC address of the destination
SA Source Address
6 bytes
The MAC address of the source
TCI Tag Control Info
2 bytes set to 8100 for 802.1p and Q tags
P Priority
3 bits
Indicates 802.1p priority level 0-7
C Canonical Indicator
1 bit
Indicates if the MAC addresses are in
Canonical format – Ethernet set to “0”
VID VLAN Identifier
12 bits
Indicates the VLAN (0-4095)
T/L Type/Length Field
2 bytes
Ethernet II “type” or 802.3 “length”
Payload < or = 1500 bytes User data
FCS Frame Check Sequence
4 bytes
Cyclical Redundancy Check
Click the folder VLAN Configuration from the Switch Management folder and then the
following screen page appears.
1. IEEE 802.1Q Tag VLAN: Configure IEEE 802.1Q Tag VLAN.
2. QinQ VLAN Configuration: Configure Q-in-Q VLAN.