You have just purchased a new Cisco 3560 switch running the enhanced IOS and need configure  it to be installed in a high availability network. On a 3560 EMI switch，
 which three types of  interfaces can be used to configure HSRP？（）

A. QoS classified at layer 3 using IP precedence or DSCP.
B. Guaranteed rate service.
C. Implemented using FIFO queues.
D. All traffic has an equal chance of being dropped.

A. Quality of Service （QoS）
B. Intelligent platforms
C. Mobility and scalability
D. Security
E. High availability

A. The IP phone is enabled to override with aCoS value of 3 the existing CoS marking of the PC  attached to the IP phone.
B. The switch will no longer tag incoming voice packets and will extend the trust boundary to the  distribution layer switch.
C. RTP will be used to negotiate aCoS value based upon bandwidth utilization on the link.  
D. Effectively， the trust boundary has been moved to the PC attached to the IP phone.
E. The computer is now establishing theCoS value and has effectively become the trust boundary.