多项选择题
A.signaling travels in-band
B.up to 24 voice channels
C.up to 32 voice channels
D.signaling travels in time slot 17
E.uses Q.931 signaling protocol in a common channel
多项选择题 Refer to the exhibit. The Greene Supply Company is integrating Cisco Unified CallManager Express into a SIP network. Which two statements are accurate?（）
单项选择题 Whichstatementbestdescribesecho?（）
单项选择题 Refer to the exhibit. The Hamilton Hair Emporium was having difficulty hearing during conference calls. This configuration adjustment was made, and now the company is experiencing sound distortion. What is the cause?（）