Figure 4-7 Formats Of Ethernet Frames; Figure 4-8 Positions Of The Tpid And Tci In The Frame Structure; Table 4-4 Tag Types Defined By Using The Tpid - Huawei OptiX OSN 550 Configuration Manual

OptiX OSN 550 Multi-Service CPE Optical Transmission
System
Configuration Guide

Figure 4-7 Formats of Ethernet frames

802.1q frame format
Destination
MAC Address
Format of the frame with
Destination
MAC Address
Format of the frame with
one S-VLAN tag nested
with one C-VLAN tag
Destination
MAC Address
The length of the data field is variable. maximum length of the data field depends on the
maximum frame length that the ports of the equipment support.
The four-byte S-VLAN or C-VLAN field is divided into two sub-fields: the tag protocol ID
(TPID) and the tag control Information (TCI).
Both the TPID and TCI consist of two bytes. See

Figure 4-8 Positions of the TPID and TCI in the frame structure

Destination
MAC Address
l
The TPID consists of two bytes and indicates the VLAN tag type. TPID of the C-VLAN is
always 0x8100 whereas the TPID of the S-VLAN can be customized. Refer to

Table 4-4 Tag types defined by using the TPID

Tag Type
C-VLAN Tag
Issue 02 (2011-06-30)
Source MAC
Address
6 bytes 6 bytes
one C-VLAN tag
Source MAC
Address
6 bytes 6 bytes
Source MAC
Address
6 bytes 6 bytes
S-VLAN
Source MAC
TPID
Address
6 bytes 6 bytes 2
bytes
2
TPID structure
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VLAN Length/Type
4 bytes 2 bytes
C-VLAN Length/Type
4 bytes 2 bytes
S-VLAN C-VLAN
4 bytes 4 bytes
Figure
C-VLAN
TCI TPID TCI
bytes bytes
2 2 2 bytes
Name
802.1q Tag Protocol Type
4 Configuring Ethernet Services
FCS Check
Data
Character
Variable
4 bytes
length
FCS Check
Data
Character
Variable
4 bytes
length
Data
Length/Type
Variable
2 bytes
length
4-8.
Length/Type
Data
Variable
2 bytes
length
Value
0x8100
FCS Check
Character
4 bytes
FCS Check
Character
4 bytes
Table 4-4.
4-9