单项选择题What best describes an FXO interface?()

A.analog trunks that provide the Survivable Remote Site Telephony (SRST) feature 
B.analog trunks that provide VoIP gateway functionality 
C.analog trunks that connect a gateway to plain old telephone service (POTS) device such as analog phones, fax machines, and legacy voice-mail systems  
D.analog trunks that connect a gateway to a central office (CO) or private branch exchange (PBX)


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2.单项选择题Which statement is true about a distributed call control environment and the processing of dialed digits from an IP phone?()

A.The router that is directly connected to the IP phone will look up the called number in its call routing table.
B.The router that is directly connected to the IP phone will inform its call agent when a service request is detected.
C.When the IP phone is picked up,the IP phone initiates the service request.
D.The directly connected router passes the collected digits to its call agent,and the call agent looks up in its call-routing table the called number.

3.多项选择题What are two major sources of delay that can be managed by QoS in voice-enabled networks?()

A.propagation delay
B.voice packet serialization delay
C.congested egress queues
D.header overhead
E.packets dropped because of CRC errors

4.多项选择题Which two statements are true about voice ports on a router?()

A.Calls to the PSTN can be made via the use of FXO or T1/E1 trunk ports.
B.Calls to the PSTN can be made via FXS or T1/E1 trunk ports.
C.Analog and IP phones can be connected to the VoIP network via FXO or T1/E1 trunk ports.
D.Calls between analog phones that are attached to the FXS ports in a VoIP network can be completely processed by voice-enabled routers.

5.单项选择题Which statement is true about Foreign Exchange Station (FXS) ports on a router?()

A.The FXS interface allows an analog connection to be directed at the public switched telephone network (PSTN’s) central office.
B.The FXS interface connects directly to a standard telephone,fax machine,or similar device and supplies ring,voltage,and dial tone.
C.The FXS interface connects directly to an IP phone and supplies ring,voltage,and dial tone.
D.The FXS interface connects directly to ISDN voice channels.

6.多项选择题Which two statements are true about the digital audio in a VoIP network?()

A.Standard encoding techniques create an uncompressed digital data rate of 4000 bps.
B.Standard encoding techniques create an uncompressed digital data rate of 8000 bps.
C.Standard encoding techniques create an uncompressed digital data rate of 64,000 bps.
D.Voice quality is not a concern if compression is not used.
E.Two methods of quantization are linear and logarithmic.
F.Two methods of compression are u-law and a-law.

7.多项选择题Which two statements are true about analog to digital conversion of voice signals for use in digital telephony networks?()

A.The three required steps in the analog to digital conversion are sampling,encoding,and compression.
B.The three required steps in the analog to digital conversion are sampling,quantization,and compression.
C.The three required steps in the analog to digital conversion are sampling,quantization,and encoding.
D.The output of the sampling process is a pulse code modulation (PCM) signal.
E.The output of the sampling process is a pulse amplitude modulation (PAM) signal.

8.多项选择题Which two statements are true about the various methods of implementing QoS?()

A.Cisco AutoQoS can be used repeatedly to apply a single QoS policy to multiple interfaces.
B.Cisco AutoQoS includes an optional web-based GUI for automating the configuration of QoS services.
C.Cisco AutoQoS provides capabilities to automate VoIP deployments.
D.The auto qos global configuration command is used to configure Cisco AutoQoS.
E.The Modular QoS CLI (MQC) is the best way to fine tune QoS configurations.
F.The SDM QoS wizard is the fastest way to implement QoS.

9.多项选择题Which two statements about the DiffServ QoS model are true?()

A.DiffServ requires RSVP to set up a path through the network to accommodate the requested QoS.
B.Network traffic is identified by class, and the level of service is chosen for each class.
C.The DiffServ model relies on a fairly simple mechanism to provide QoS over a wide range of equipment.
D.RSVP enables the DiffServ model to provide end-to-end QoS.
E.The DiffServ model is more scalable than the IntServ model.
F.The flow-based approach of the DiffServ model is ideal for large scalable implementations such as the public Internet.

10.单项选择题What form of AutoQoS is supported on Cisco Catalyst 2950 switches with the Enhanced Image?()

A.AutoQos Enterprise
B.AutoQoS Campus
C.AutoQoS VoIP
D.AutoQoS LAN