Which two of these are differences between traffic policing and traffic shaping？（）

• A、with traffic shaping，a router stores excess traffic in packet buffers until bandwidth is available again
• B、with policing you can tune the buffer usage for traffic exceeding the specified CIR
• C、with shaping you can tune the buffer usage for traffic exceeding the specified CIR
• D、shaping should only be applied for ingress traffic，policing only for egress
• E、policing uses a token bucket algorithm，shaping uses an SPD algorithm