A. connects traditional telephony devices to voice over……

多项选择题Whichtwocharacteristicsarecommonbetweentrafficpolicingandtrafficshaping？（）

A. The rate of traffic is measured and compared to a configured policy.
B. Classification is used to differentiate traffic.
C. Traffic is marked and sent out according to priority.
D. Both can be applied to inbound and outbound traffic.
E. Both buffer traffic to ensure a predetermined traffic rate.
F. Both drop traffic that is above a predetermined traffic rate.

多项选择题WhichtwoQoSclassificationandmarkingstatementsaretrue？（）

A. In a Frame Relay network， delay sensitive traffic is tagged with the discard eligible （DE） bit.
B. In an MPLS network， the three most significant bits of the DSCP or the IP precedence of the IP packet are copied into the MPLS EXP field.
C. In an MPLS network， the MPLS EXP bits are used to identify up to 16 CoS values.
D. The differentiated services code point （DSCP） field consists of the first three bits of the IP precedence field in the header of an IP packet.
E. The 802.1Q standard uses a three bit field referred to as the user priority bits （PRI） to mark packets as belonging to a specific CoS.

单项选择题Whatisthetermthatisusedtodescribetheprocessofconvertingasignalfromdigitaltoanalog？（）

A. packetization
B. quantization
C. decoding
D. sampling

多项选择题WhataretworeasonstoimplementH·323gatekeepers？（）

A. to eliminate the need for VoIP gateways
B. to scale a VoIP installation with multiple gateways
C. to provide call admission control and limit the number of simultaneous calls on the network 
D. to meet the requirement to control H·323 gateways on a LAN
E. to accept call requests and reduce the load on the gateway

多项选择题WhatarethreefactorsusedtodeterminetheamountofbandwidththatisrequiredforasingleVoIPcall？（）

A. codec
B. link speed
C. Layer 2 encapsulation
D. packet overhead （IP/UDP/RTP）
E. link delay
F. total number of simultaneous calls that are allowed