The SAP link-type parameter instructs STP on the maximum number of bridges behind this SAP. If there is only a single bridge, transitioning to forwarding state is based on handshaking (fast transitions). If more than two bridges are connected by a shared media, their SAPs should all be configured as shared, and timer-based transitions are used.
Valid values for SAP link-type are shared and pt-pt with pt-pt, being the default.
CLI syntax:
config>service>vpls>sap>stp#
link-type {pt-pt | shared}