ZyXEL Communications MSC1000G User Manual page 210

Chapter 9 Subscriber Port Setup Screens
Figure 128 VLAN Stacking Example
9.2.13.1 VLAN Tag Format
A VLAN tag (service provider VLAN stacking or customer IEEE 802.1Q) consists of the following
three fields.
Table 91 VLAN Tag Format
Type
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. The system use 0x8100.
TPID (Tag Protocol Identifier) is the customer IEEE 802.1Q 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 the 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.
9.2.13.2 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 circled in the switch VLAN Stacking screen.
Table 92 Single and Double Tagged 802.1Q Frame Format
DA
DA SA SPTPID Priority VID TPID
210
Priority VID
DA SA
SA TPID Priority VID
Priority VID
Len/Etype Data FCS
Len/Etype Data FCS
Len/Etype Data FCS
Management Switch Card User's Guide
Untagged Ethernet frame
IEEE 802.1Q customer
tagged frame
Double-tagged frame