Alcatel-Lucent 7210 SAS M Service Manual page 284

VPLS Features
The draft definition message is currently used in management VPLS which is using RSTP for
recovering from failures in Layer 2 topologies. The mechanism described in this document
represent an alternative solution.
The advantage of this approach (as compared to RSTP based methods) is that only MAC-affected
addresses are flushed and not the full forwarding database. While this method does not provide a
mechanism to secure alternative loop-free topology, the convergence time is dependent on the
speed of the given CE device will open alternative link (L2-B switch in
the speed PE routers will flush their FDB.
In addition, this mechanism is effective only if PE and CE are directly connected (no hub or
bridge) as it reacts to physical failure of the link.
Page 284
Figure 46) as well as on
7210 SAS M Services Guide