Ericsson EFN324, User Manual, Page: 18 / 176

IndexIndex
Figure 6 IEEE 802.1Q tag
EFN324 supports zero, one and two VLAN tags as described above. Within
the CLI and in the MIB, the terms ‘tag’ and ‘second_tag’ are used for historical
reasons, but there is no direct mapping to the more common terms “Outer and
Inner VLAN tag”.
Pre­
am­
ble
Dest.
address
Source
address
Type/
length
field
Frame
check
sequence
Data (0 – 1500 bytes)
and
Pad (46 – 0 bytes)
Original (”DIX type II”)
Ethernet frame; also called “untagged”:
Dest.
address
Source
address
Type/
length
field
Frame
check
sequence
Data
and
Pad
8 bytes 6 bytes 6 bytes 4 bytes 2 bytes 46 – 1500 bytes 4 bytes
802.1Q VLAN tagged
Ethernet frame:
Pre­
am­
ble
802.1Q
VLAN
Tag
Tag
Protocol
Identifier
(0x8100)
User priority CFI VLAN ID
3 bits 1 bit 12 bits
Tag Control Information
2 bytes 2 bytes
8 bytes 6 bytes 6 bytes 2 bytes 46 – 1500 bytes 4 bytes