Frame Format; Configuring Vlan Stacking - ZyXEL Communications GS3700 Series User Manual

Type is a standard Ethernet type code identifying the frame and indicates that whether the frame
carries IEEE 802.1Q tag information. SP TPID (Service Provider Tag Protocol Identifier) is the
service provider VLAN stacking tag type. Many vendors use 0x8100 or 0x9100.
TPID (Tag Protocol Identifier) is the customer IEEE 802.1Q tag.
• If the VLAN stacking port role is Access Port, then the Switch adds the SP TPID tag to all
incoming frames on the service provider's edge devices (1 and 2 in the VLAN stacking example
figure).
• If the VLAN stacking port role is Tunnel Port, then the Switch only adds the SP TPID tag to all
incoming frames on the service provider's edge devices (1 and 2 in the VLAN stacking example
figure) that have an SP TPID different to the one configured on the Switch. (If an incoming
frame's SP TPID is the same as the one configured on the Switch, then the Switch will not add
the tag.)
Priority refers to the IEEE 802.1p standard that allows the service provider to prioritize traffic
based on the class of service (CoS) the customer has paid for.
• On the Switch, configure priority level of the inner IEEE 802.1Q tag in the Port Setup screen.
• "0" is the lowest priority level and "7" is the highest.
VID is the VLAN ID. SP VID is the VID for the second (service provider's) VLAN tag.

21.3.1 Frame Format

The frame format for an untagged Ethernet frame, a single-tagged 802.1Q frame (customer) and a
"double-tagged" 802.1Q frame (service provider) is shown next.
Configure the fields as highlighted in the Switch VLAN Stacking screen.
Table 78 Single and Double Tagged 802.11Q Frame Format
DA SA SPTPID
Table 79 802.1Q Frame
DA
SA
(SP)TPID
VID

21.4 Configuring VLAN Stacking

Click Advanced Application > VLAN Stacking to display the screen as shown.
Chapter 21 VLAN Stacking
DA SA
Priority VID
Destination Address
Source Address
(Service Provider) Tag Protocol IDentifier
VLAN ID
GS3700/XGS3700 Series User's Guide
DA SA
TPID Priority VID
TPID Priority VID
Priority
Len/Etype
Data
FCS
172
Len/Etype Data FCS
Len/Etype Data FCS
Len/Etype Data FCS
802.1p Priority
Length and type of Ethernet frame
Frame data
Frame Check Sequence
Untagged
Ethernet frame
IEEE 802.1Q
customer
tagged frame
Double-tagged
frame