Zyxel OLT2412 [162/326] Frame format

Chapter 23 VLAN Stacking and Translation

OLT2412 User’s Guide

162

23.3.1 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.

23.4 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.

23.5 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.

Table 83 Single and Double Tagged 802.11Q Frame Format

DA SA Len/

Etype

Data FCS Untagged Ethernet

frame

DA SA TPID Priority VID Len/

Etype

Data FCS

IEEE 802.1Q

customer tagged

frame

DA SA SPTPID Priority VID TPID Priority VID Len/

Etype

Data FCS

Double-tagged

frame

Table 84 802.1Q Frame

DA Destination Address Priority 802.1p Priority

SA Source Address Len/Etype Length and type of Ethernet frame

(SP)TPID (Service Provider) Tag Protocol IDentifier Data Frame data

VID VLAN ID FCS Frame Check Sequence