ZyXEL Communications OLT2406, User Manual

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Chapter 24 VLAN Stacking
OLT2406 User’s Guide
192
Figure 117
VLAN Stacking Example
24.2 VLAN Stacking Port Roles
Each port can have three VLAN stacking “roles”, Normal , Access Port and Tunnel Port (the latter is for
Gigabit ports only).
• Select Normal for “regular” (non-VLAN stacking) IEEE 802.1Q frame switching.
• Select Access Port for ingress ports on the service provider's edge devices ( 1 and 2 in the VLAN
stacking example figure). The incoming frame is treated as "untagged", so a second VLAN tag (outer
VLAN tag) can be added.
Note: Static VLAN Tx Tagging MUST be disabled on a port where you choose Normal or
Access Port .
• Select Tunnel Port (available for Gigabit ports only) for egress ports at the edge of the service
provider's network. All VLANs belonging to a customer can be aggregated into a single service
provider's VLAN (using the outer VLAN tag defined by the Service Provider’s (SP) VLAN ID (VID)).
Note: Static VLAN Tx Tagging MUST be enabled on a port where you choose Tunnel Port .
24.3 VLAN Tag Format
A VLAN tag (service provider VLAN stacking or customer IEEE 802.1Q) consists of the following three
fields.
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.
Table 64
VLAN Tag Format
Type Priority VID