单项选择题
A.queuing
B.jitter
C.packet loss
D.digitized sampling
E.signal-to-noise ratio ratio
多项选择题 Refer to the exhibit. Which two of these are correct regarding the recommended practice for distribution layer design？（）
单项选择题 You are the Cisco Network Designer in Cisco.com. Which of these statements is true of clientless end-user devices?（）
多项选择题 What are two design guidelines for VoIP networks? （）