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.