ZyXEL VES1724-56B2 User Guide - Page 209

Chapter 23 VLAN Stacking adding tag 37 to distinguish customer A and tag 48 to distinguish customer B at edge device 1 and then stripping those tags at edge device 2 as the data frames leave the network. Figure 125 VLAN Stacking Example 23.2 VLAN Stacking Port Roles Each port can have three VLAN stacking "roles", Normal, Access Port and Tunnel (the latter is for Gigabit ports only). Note: Some devices do not support all roles. • 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. VES1724-56 User's Guide 209