APRICOT 2011 - MPLS-based Metro Ethernet Networks v1.0

Traditional Metro Ethernet Networks
Service Identification:
Some important observations about Q-in-Q:
This is not a new encapsulation format; it simply results in the addition of a second
tag to the customer Ethernet frame, allowing any customer VLAN tags to be
preserved across the network
There is no change to the customer destination or source MAC addresses
The number of distinct service instances within each Provider Bridging domain is
still limited by the S-VLAN ID space i.e. 4094 S-VLANs. The difference is that
customer VLANs can now be preserved and carried transparently across the
provider network.
34 | MPLS-based Metro Ethernet Networks, February 2011