As with Layer 2 MCT, VPLS or VLL MCT
uses Cluster Control Protocol (CCP) for the control plane. A PW-Client ID controls all
pseudowires.
The bridge domain is mapped to a CCP instance.
For each BD, the default CCP ID is the BD ID plus 4,096. A user configured CCP ID is not
supported. The CCP ID for the VLAN is the VLAN ID.
For VPLS or VLL MCT, the physical and LAG CCEP operate in active/active multi-homing mode. However, the PW operates in active/standby mode.
The designated forwarder (DF) state of the
PW-Client ID represents the active PW node state for a VPLS or VLL instance. The DF
election process for the PW ESI is the same as the Layer 2 process. However, VPLS and
VLL MCT in the following dynamic cases do not change their role, and are driven through
the PW horizon client.
If the local endpoint is down, the
remote endpoint is up.
If the active-active PW is down on the
active node, the PW on the standby node will not change to active-active.
