单项选择题
A.WRED
B.traffic shaping
C.packet marking
D.packet classification
E.FIFO queuing within the class
单项选择题 Refer to the exhibit. Which switching feature is being tested？（）
问答题 R1（AS1）------R2（AS2）-----R3（AS2）----R4（AS2） ，R1在AS1，R2，R3，R4在AS2，R1和R2建EBGP ， R2和R3 IBGP，R3和R4 IBGP，产生BGP路由从R1传给R2，问这条路有会不会在R4上出现，如果不会，怎么解决.
单项选择题 Refer to the exhibit. Voice traffic is marked "precedence 5." How much bandwidth is allocated for voice traffic during periods of congestion？（）
