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Chapter 75 VLAN Stacking and Translation
OLT2406 User’s Guide
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HAPTER
75
VLAN Stacking and
Translation
75.1 VLAN Stacking Overview
This chapter shows you how to configure VLAN stacking and VLAN translation on your OLT. See Chapter
56 on page 440 for more background information on Virtual LAN.
A service provider can use VLAN stacking to allow it to distinguish multiple customers VLANs, even those
with the same (Customer-assigned) VLAN ID, within its network.
Use VLAN stacking to add an outer VLAN tag to the inner IEEE 802.1Q tagged frames that enter the
network. By tagging the tagged frames (“double-tagged” frames), the service provider can manage
up to 4,094 VLAN groups with each group containing up to 4,094 customer VLANs. This allows a service
provider to provide different service, based on specific VLANs, for many different customers.
A service provider’s customers may require a range of VLANs to handle multiple applications. A service
provider’s customers can assign their own inner VLAN tags on ports for these applications. The service
provider can assign an outer VLAN tag for each customer. Therefore, there is no VLAN tag overlap
among customers, so traffic from different customers is kept separate.
75.1.1 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).
• Use normal for “regular” (Non-VLAN stacking) IEEE 802.1Q frame switching.
• Use 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 inner tagged or untagged, so a second VLAN tag
(outer VLAN tag) can be added.
Note: If you use Q in Q, static VLAN Tx tagging must be enabled on a port set to the normal or
access port role.
Otherwise static VLAN Tx Tagging must be disabled on a port set to the normal or
access port role.
• Use 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)).