Frame Format; Port-Based Q-In-Q; Selective Q-In-Q - ZyXEL Communications OLT2406 User Manual

• If the VLAN stacking port role is access port, then the OLT 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).
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 OLT, configure priority level of the inner IEEE 802.1Q tag.
• "0" is the lowest priority level and "7" is the highest priority level.
VID is the VLAN ID. SP VID is the VID for the second (Service provider's) VLAN tag.

75.3.1 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.
Table 269 Single and Double Tagged 802.11Q Frame Format
DA SA SPTPID
Table 270 802.1Q Frame
DA
SA
(SP)TPID
VID

75.4 Port-based Q-in-Q

Port-based Q-in-Q lets the OLT treat all frames received on the same port as the same VLAN flows and
add the same outer VLAN tag to them, even if they have different customer VLAN IDs.

75.5 Selective Q-in-Q

Selective Q-in-Q is VLAN-based. It allows the OLT to add different outer VLAN tags to the incoming
frames received on one port according to their inner VLAN tags.
Note: Selective Q-in-Q rules are only applied to single-tagged frames received on the access
ports. If the incoming frames are untagged or single-tagged but received on a tunnel
port or cannot match any selective Q-in-Q rules, the OLT applies the port-based Q-in-Q
rules to them.
Chapter 75 VLAN Stacking and Translation
DA SA
Priority VID
Destination Address
Source Address
(Service Provider) Tag Protocol IDentifier
VLAN ID
OLT2406 User's Guide
DA SA Len/Etype
TPID Priority VID Len/Etype
TPID Priority VID Len/Etype
Priority
Len/Etype
Data
FCS
528
Data FCS Untagged Ethernet
frame
Data FCS IEEE 802.1Q customer
tagged frame
Data FCS Double-tagged
frame
802.1p Priority
Length and type of Ethernet frame
Frame data
Frame Check Sequence