Vlan Tunnel - Siemens SCALANCE XM-400 Configuration Manual

Technical basics
4.4 VLAN
4.4.4

VLAN tunnel

With the Q-in-Q VLAN Tunnel function it is possible to forward the data traffic from different
customer networks using a VLAN tunnel via a provider network. Every customer network has
the full number of possible VLANs available.
A VLAN tunnel is established between provider switches that are configured at the boundaries
of a provider network. A provider switch has the following types of ports:
● Access port
The provider switch is connected to a customer network via an access port.
– Incoming data traffic
– Outgoing data traffic
● Core port
The provider switch is connected to a provider network via a core port.
Core ports are members in the port VLAN of the access port or configured with the port
type "Switch-Port VLAN Trunk".
Customer network A
VLAN ID
Customer network B
Priority
Customer network C
untagged
42
The incoming data traffic at an access port is treated as if it were untagged
incoming frames are expanded by a tag with the port VID of the access port
frames that are already tagged, this means they are expanded by a second 802.1Q tag
③
the outer VLAN tag.
With outgoing data traffic the outer tag is removed again at an access port.
Provider network
Customer network A
VLAN ID
Customer network B
Priority
Customer network C
untagged
SCALANCE XM-400/XR-500 Web Based Management (WBM)
Configuration Manual, 05/2017, C79000-G8976-C248-12
①
. All
②
. With