1. Large Scale Q-in-Q
1. Scaling address learning

2. Provider Priority Discussion
Perceived problem
As a Provider Bridged Network grows and attracts more customers it will contain more Provider Bridges that learn the addresses of each customer so the total amount of address learning:
= fn(#of customers x #of Provider Bridges)
= fn(#of customers2)
= fn(value provided2)
802.1 June ‘03
Provider Priority Discussion

3. Provider Priority Discussion
Preliminary answer
Don’t learn on point-to-point Service Instances
But what about Services Instances with more than 2 points of attachment?
802.1 June ‘03
Provider Priority Discussion

4. Provider Priority Discussion
Better answer
Don’t learn unless the learning will affect where frames are forwarded e.g. don’t learn when
Receiving port is attached to point-to-point LAN
There are less than two ports on this bridge that are in the (egress) Member set for this VLAN
802.1 June ‘03
Provider Priority Discussion

5. Provider Priority Discussion
Making the best of this
Use GVRP to scope the extent of the Service VLAN so extent of VLAN is minimal over its Spanning Tree but extent of VLAN autoconfigures after active topology reconfiguration
For S-VLAN with 3 customer attachments learning only required in 1 provider bridge
For S-VLAN with n customer attachments learning only required in (n-2) provider bridges at most
Minimizes database flushing impact after change
802.1 June ‘03
Provider Priority Discussion

6. Provider Priority Discussion
Shared VLANs
Some stations transmit on A, receive on B
Others receive on A, transmit on B
Allows multiple subscribers to be served using one customer network
802.1 June ‘03
Provider Priority Discussion

7. Optimizing learning on shared VLANs
Only learn addresses from frames on VLAN A if VLAN B has more than one way for a frame that has entered a bridge to leave
802.1 June ‘03
Provider Priority Discussion

8. LARGE scale with shared VLANs
Routers/servers here
Addresses of subscribers (below) only learnt in this bridge and below
Subscribers attached to these bridges
802.1 June ‘03
Provider Priority Discussion