Which statements about MPLS Label Distribution Protocol（LDP） are valid？（）

A.DPT/RPR uses a bi-directional ring consisting of two symmetric counter rotating fibre rings.
B.DPT/RPR is defined in the IEEE 802.17 standard and it uses Token Bucket system to avoid collisions on the fiber.
C.In DPT/RPR rings， data packets can be sent in one direction （downstream） and the corresponding control packets in the opposite direction （upstream），thus using both fibres concurrently to maximise bandwidth.
D.DPT/RPR can be deployed in the Core of the SP networks where point-to-point POS links are used tomake best use of the Bandwidth.

A.The configuration to define Route-Distinguisher is Ip vrf bulle Rd 1：1
B.A route distinguisher can be imported and exported to and from a VRF
C.Route-Distinguisher is an 8 byte BGP attribute value used in influencing BGP best path algorithm.
D.Route-Distinguisher is an 8 byte value used in creating unique VPNv4 address.

A.Control Plane Policing （CoPP） addresses the need to protect the management planes， ensuring routingstability， availability， and critical packet delivery.
B.Control Plane Policing （CoPP） leverages MQC to define traffic classification criteria and to specifyconfigurable policy actions for the classified traffic.
C.Control Plane Policing （CoPP） uses a dedicated "control-plane" command via the Modular QoS CLI （MQC）to provide filtering and rate limiting capabilities.
D.Control Plane Policing （CoPP） uses "service policy" command under relevant interfaces to filter DOS packet to protect routing packets.
E.Control Plane Policing （CoPP） protects the transit management and data traffic through the router.