Cisco Voice Over IP

1.You are working with a potential customer that would like to integrate its existing PBX telephone system into its IP network. The accompanying figure shows that the customer has two offices that need to be connected to the IP network so that the customer can exchange telephone calls without using the PSTN. Both PBXs are currently connected to T1 ISDN circuits. Which signaling type will allow you to support your customer?

A.QSIG
B.CCS
C.CAS
D.T-CCS
E.E&M
F.FXO
Correct:C
2.You are meeting with a customer that has deployed IP telephony at their headquarters location. They would like to roll out IP telephony to their regional office as well. They are now using the G.711 codec at headquarters. They want to be able to maximize the number of calls carried without impacting voice quality or forcing a WAN upgrade. Which codec would be appropriate for their WAN?
A.G.726
B.G.723.1
C.G.711
D.G.729B
Correct:D
3.Refer to the exhibit. Users are not able to complete a call from 678-555-1212 to 770-555-1111. What is the correct diagnosis for the problem?

A.incorrect dial-peer statement in Router 1
B.incorrect port statement in Router 1 pots dial peer
C.incorrect session-target statement in Router 2
D.incorrect destination-pattern in Router 1
Correct:D
4.You have been forwarded some questions by a prospective VoIP customer who would like to know the Cisco default sample size for the G.729 codec. What is it?
A.40 ms
B.30 ms
C.20 ms
D.10 ms
Correct:C
5.Examine the example output. Hostname GW1 ! Interface Ethernet 0/0 ip address 172.16.2.1 255.255.255.0 h323-gateway voip interface h323-gateway voip id GK1-zone1.abc.com abc.com ipaddr 172.16.2.2 h323-gateway voip h323-id GW1 h323-gateway voip bind srcaddr 172.16.2.1 ! Dial-peer voice 1 voip destination-pattern 1212. session-target ras ! Dial-peer voice 2 pots destination-pattern 2125551212 no register e164 ! End Choose the command that will restore communication with gatekeeper functionality to this device.
A.h323-gateway voip h323-id GK1
B.gateway
C.h323-gateway voip bind srcaddr 172.16.2.2
D.h323-gateway voip GW1-zone2.abc.com abc.com ipaddr 172.16.2.1
Correct:B
6.Which preference key word assigns top precedence to a dial peer in a hunt-group?
A.0
B.priority
C.1
D.high
Correct:A
7.You are working with a potential customer that would like to integrate its existing PBX telephone system into its IP network. The accompanying figure shows that the customer has two offices that need to be connected to the IP network so that the customer can exchange telephone calls without using the PSTN. Both PBXs use Wink-Start signaling. Which signaling type will allow you to support the customer?

A.QSIG
B.CCS
C.CAS
D.T-CCS
E.E&M
F.FXO
Correct:E
8.A 9 digit number must be dialed to reach numbers on the PSTN. What process makes sure that the first digit 9 is not transmitted as part of the called number?
A.digit alternating
B.digit masking
C.digit manipulation
D.digit seizing
Correct:C
9.What is the E.164 numbering plan?
A.a proprietary PBX number plan
B.the IETF North American number plan
C.the European PBX standard telephony number plan
D.the ITU worldwide number plan
Correct:D
10.Refer to the exhibit. What is the minimum WAN bandwidth required to support three simultaneous VoIP calls in this network?

A.19,200 bps
B.51,600 bps
C.79,200 bps
D.247,200 bps
Correct:B
11.In the connection between a Cisco router and an E&M port on a PBX, which side is generally the Cisco side?
A.loop start
B.trunk circuit
C.switch port
D.signaling unit
Correct:D
12.Which dial plan characteristic shows the most obvious improvement by dropping a number translation step?
A.availability
B.post-dial delay
C.scalability
D.hierarchical design
Correct:B
13.What are two basic parameters needed to setup a dial peer connected to the PSTN? (Choose two.)
A.voice port
B.signaling type
C.interface bandwidth
D.destination pattern
Correct:A D
14.Which device is used to allow an H.323 stream to transit a firewall?
A.gatekeeper
B.gateway
C.proxy
D.MCU
Correct:C
15.You are working with your customer in their lab to test the effect of jitter on voice quality. You have set the maximum playout delay to 40 ms on the voice enabled routers. What will be the impact on voice quality if after severe congestion the playout buffer empties and the source sends packets to the buffer faster than they are leaving?
A.There will be no noticeable drop in quality.
B.The jitter buffer will adapt to the faster-arriving packets by expanding the buffer size.
C.The jitter buffer will speed up delivery of packets to the DSP so that packets are not dropped.
D.After the jitter buffer fills up, subsequent packets are discarded.
Correct:D
16.Refer to the exhibit. Your customer wants to converge voice and data on the existing T1 Frame Relay WAN link between New York and Atlanta. The customer has allocated 25 percent of the WAN link for routing updates and other overhead. You are using 6 bytes of overhead for Frame Relay, no cRTP, and the G.729 codec. How many calls could be placed on this link?

A.two
B.three
C.four
D.five
E.six
F.seven
Correct:C
17.In a VoIP environment when speech samples are framed every 20 ms, a payload of 20 bytes is generated. Assuming a total packet length of 60 bytes, what is the length of the packet header if cRTP is deployed without redundancy checks?
A.1 byte
B.2 bytes
C.3 bytes
D.4 bytes
E.20 bytes
F.40 bytes
Correct:B
18.You have a customer that is interested in determining the number of VoIP calls their Frame Relay WAN links can support. Each of their Frame Relay WAN links has 84 kbps of bandwidth available outside all other applications and overhead. How many G.729 calls using the 8 kbps codec and 20 byte sample size can be supported?
A.1
B.2
C.3
D.4
Correct:C
19.You are working with a potential customer that would like to integrate its existing PBX telephone system into its IP network. The accompanying figure shows that the customer has two offices that need to be connected to the IP network so that the customer can exchange telephone calls without using the PSTN. Both PBXs use an in-band signaling type. Which signaling type will allow you to support your customer?

A.QSIG
B.CCS
C.CAS
D.T-CCS
E.E&M
F.FXO
Correct:C
20.A network has the following characteristics: ?the use of the G.711 codec with a codec speed of 64 kbps ?a 160-byte sample size ?the use of Frame Relay without compressed Real-Time Transport Protocol (CRTP) ?FRF.12 with 6 bytes of overhead What minimum WAN bandwidth would be required to support three simultaneous VoIP calls?
A.247200 bps
B.19200 bps
C.79200 bps
D.51600 bps
Correct:A
21.At what point does the MGCP call agent release the setup of the call path to the residential gateways?
A.after the call agent has been notified that an event occurred at the source residential gateway
B.after the call agent has been notified of an event and has instructed the source residential gateway to create a connection
C.does not release call path setup
D.after the call agent has sent a connection request to both the source and destination and has relayed a modify-connection request to the source so that the source and destination can set up the call path
E.after the call agent has forwarded session description protocol information to the destination from the source and has sent a modify connection to the destination and a create-connection request to the source
Correct:D
22.Refer to the exhibit. You have been asked to configure a dial peer on R2 that will match only the extensions of the four telephones attached. Which dial-peer statement will you use?

A.dial-peer voice 1 pots destination-pattern 5552.[0-5]0
B.dial-peer voice 1 pots destination pattern 5552[5-6].0
C.dial-peer voice 1 pots destination-pattern 555[2-5][56]
D.dial-peer voice 1 pots destination-pattern 5552[5-6][05]0
Correct:D
23.King's Mountain Cable has a pair of voice enabled routers capable of supporting only high complexity codecs. They need to conserve bandwidth on WAN links without major impact to call quality. Which two codecs satisfy these requirements? (Choose two.)
A.G.729
B.G.729a
C.G.729b
D.G.729ab
Correct:B D
24.Which gateway interface connects to the standard station port of a PBX?
A.FXS
B.E&M
C.POTS
D.FXO
Correct:D
25.Your customer has forwarded this diagram and configuration. The customer wishes to have a connection between its PBXs, a connection that is created and dropped as required. There is one configuration statement missing from each router. What are the two missing statements? (Choose two.)

A.connection trunk 2015551000404555?
B.connection trunk 4045551200
C.connection tie-line 4045551200
D.connection tie-line 404555?
E.connection tie-line 2015551000
F.connection trunk
Correct:C E
26.Refer to the exhibit. What is the minimum WAN bandwidth required to support three simultaneous VoIP calls in this network?

A.19,200 bps
B.51,600 bps
C.79,200 bps
D.247,200 bps
Correct:C
27.Which process changes an internal extension into a fully qualified external PSTN number before matching to a dial peer?
A.digit masking
B.forward digits
C.number expansion
D.prefix extension
Correct:C
28.Which type of signaling is DTMF?
A.supervisory
B.route
C.informational
D.address
Correct:D
29.Which type of delay is caused when large data packets block voice packets from the outbound interface?
A.queuing delay
B.serialization delay
C.propagation delay
D.packetization delay
Correct:A
30.Drop

Correct:
Green choice2---->Yellow Choice1
Green choice3---->Yellow Choice2
Green choice1---->Yellow Choice3
Green choice5---->Yellow Choice4
Green choice4---->Yellow Choice5