单项选择题
A. determine types of protocols to be supported
B. determine the environment in which the router will be used
C. select the number of WAN ports required
D. select the number of LAN ports required
多项选择题 Dense Wavelength Division Multiplexing (DWDM) is an important innovation in optical networks.Which two descriptions best define DWDM?（）
多项选择题 You are the network consultant from Cisco.com. Please point out two statements correctly describe an IPS device（）
单项选择题 Users at the Charleville Company began experiencing high network delays when Internet connectivity was enabled for all users. After investigating the traffic flow, you determine that peerto-peer traffic from a music download site is consuming a large amount of bandwidth. Which QoS mechanism can you implement to improve the network response time?（）