ES-3124 User’s Guide

Figure 68 VLAN Stacking Example

21.2 VLAN Stacking Port Roles

Each port can have three VLAN stacking “roles”, Normal, Access Port and Tunnel (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 SP VID).

Note: Static VLAN Tx Tagging MUST be enabled on a port where you choose

Tunnel Port.

21.3 VLAN Tag Format

A VLAN tag (service provider VLAN stacking or customer IEEE 802.1Q) consists of the following three fields.

Table 48 VLAN Tag Format

Type

Priority

VID

 

 

 

164

Chapter 21 VLAN Stacking