Legend:
TPID Tag protocol identifier (“Ethertype”) - indicates the presence of
a VLAN tag (or CID tag, respectively). Furthermore, it
indicates that the length/type field can be found at a different
position in the frame (moved by 4 bytes).
UP (3 bits) User priority - “0” (low priority) { “7” (high priority).
CFI (1 bit) Canonical Format Identifier - indicates the presence or absence
of routing information.
Destination address
IEEE 802.1Q VLAN tagging mode
VPN tagging mode /
IEEE 802.1ad VLAN tagging mode
Destination address
VLAN tag (C-tag) CID-tag (S-tag)
VLAN tag (C-tag)
TPID
UP
CFI
VID
(V ...V )
811
Length/Type
Length/Type
Source address Source address
Payload
Payload
66
66
44
4
4
4
2
2
46 - 1500
46 - 1500
MAC frame
(64 - 1522 bytes)
MAC frame
(68 - 1526 bytes)
FCS
FCS
2
2
VID (V ...V )
17
TPID (e.g.0x9100)
S-tag
S-VID (cont.)
S-VIDS-UP
S-CFI
v
11
,v
10
,v
9
,v
8
v
7
,v
6
,v
5
,v
4
,v
3
,v
2
,v
1
,v
0
p
2
,p
1
,p
0
TPID
C-tag
(cont.)
C-CFI
v
11
,v
10
,v
9
,v
8
v
7
,v
6
,v
5
,v
4
,v
3
,v
2
,v
1
,v
0
p
2
,p
1
,p
0
C-UP
C-VID
(0x8100)
C-VID
Ethernet Overview
Tagging modes
....................................................................................................................................................................................................................................
11-40
Alcatel-Lucent - Proprietary
See notice on first page
365-312-801R7.2
Issue 3, May 2007
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