CCNA Voice Practice Tests – PSTN and Service Provider Networks (1-5)

Topic 4 – PSTN and Service Provider Networks

Question 1
Which of the following is selected first for an incoming dial peer?
B.incoming called-number
D.pots port
Answer: B

This question tests the matching procedure of an incoming dial-peer.
The incoming dial-peer match can be divided into pots dial-peer incoming match and voip incoming dial-peer match. The pots dial-peer incoming match requires four matching conditions, and the procedure is:
1. incoming called number;
2. answer-address;
3. destination-pattern;
4. pots port voip dial-peer: there is no match of pots port and it only has the former three matching conditions.

Question 2
Choose the Gateway to the proper locations.
Answer: C
This question tests the function of voice gateway.
There are three functions of voice gateway.
1. Media translation, that is, the translation between the Ethernet lines and the traditional PSTN lines.
2. Signaling translation, that is, IP signaling, such as H323, MGCP, SIP and traditional signaling (e.g. translation between ISDN and SS7).
3. The medium translation, that is, the translation between IP packet of IP voice, TDM digital voice of traditional voice and analog voice of continuous signals. 
Voice gateway is used between two different kinds of voice networks and it plays the above-mentioned three roles. Therefore, choose C.

Question 3
You are CCNA VOICE associate in Which two are considered endpoints in a Cisco Unified Communications solution?
A.router agent
C.IP telephone
Answer: C D
The point of this question is to examine which devices within voice ccna’s scope belong to the terminal devices in CUCM solutions.
CUCM is the core of the entire UC solutions. All the application server, gateway and IP Phone must rely on CUCM to accomplish cooperative work.
A: Router: Not all the routers can serve as the voice gateway in the UC solutions, which depends on the hardware platform and IOS version.
B: call agent: The call agent is a UC management component. In Cisco UC solutions, call agent is generally considered as the CUCM.
C: IP Phone: an end-point in a CUCM
D: gateway: Within the scope of voice, the gateway generally refers to the network devices with voice processing capability. The device can be a router, Switches modular or VG248, ATA and other analog gateways. It is an end-point in CUCM.

Question 4
What device enables Call Admission Control in a CME environment?
Answer: D
management and address resolution.
This question tests the functions of each UC device in a CME environment.
A: gateway, that is, the voice gateway. Its functions are:
1. Medium translation;
2. Signaling translation
3. Media translation
B: transcoder: mainly refers to DSP resources or separate transition points.
C: Bridge: conference bridge. Its main role is to provide resources during the conference.
D: gatekeeper: It enables Call Admission Control in a CME environment to perform call
Question 5
You are CCNA VOICE associate in You need configure PSTN voice gateway. Which two dial peers will correctly route calls to emergency services?
A.dial-peer voice 1 pots
destination-pattern 9911
prefix 911
port 1/0/0
B.dial-peer voice 2 pots
destination-pattern 911
forward-digits all
port 1/0/0
C.dial-peer voice 9911 pots
destination-pattern 9911
forward-digits all
port 1/0/0
D.dial-peer voice 2 pots
destination-pattern 911
forward-digits 3
port 1/0/1
Answer: A B
There is a number-eating principle in the traditional voice, which means that exact matching numbers will be eaten instead of being sent to the CO. Therefore, these exact matching numbers have to be completed before being sent.
A is right.
B is right.
C: The called number is 9911 other than 911. There is no corresponding number in CO.
D: Ports port is wrong.