Tài liệu Cisco IP Telephony- Enterprise Voice Over Data Design Test docx

Cisco Design Essentials: Cisco IP Telephony
-
Enterprise Voice Ove
r Data Design Test

1)
Which of the following is a proprietary Nortel PBX protocol?
a. DCS
b. DPNSS
c. MCDN
d. CORNET
2)
It is generally recommended that IP Phones be supplied static addressing.
a. True
b. False
3)
Which of the following statements are true about FRF.12?
a. It fragments a large frame into multiple smaller frames and reassembles it at the destination
end
b. It ignores FRF.11 frames
c. It needs a queuing mechanism to interleave voice frames with the fragmented frames
d. A, B, and C
e. A and B
f. B and C
g. A and C
4)
Would it be more appropriate to implement RSVP or CBWFQ/IP Precedence for a voice call over a data
network?

a. RSVP
b. CBWFQ/IP Precedence
5)
Which of the following statements are true of CallManager 2.4 multi-site WAN-distributed call processing?
a. A CallManager and MTP is required at each location
b. A Cisco IOS gatekeeper is required for admission control
c. A minimum of Cisco IOS gateway of IOS 12.0(6)T is required
d. G.711 only for all IP WAN voice calls
e. All of the above
f. B and D only
6)
To support a conference of three or more H.323 terminals, a ______ is required.
a. Multipoint control unit (MCU)
b. Gatekeeper
c. Gateway
7)
Consider this scenario. You want to connect your
IP Telephony network to the central office switch using E1 (or
T1 PRI). Which of the following choices is an appropriate gateway selection?

a. the DT-24+ (or DE-30+) IP Telephony gateway
b. AS5300 Cisco IOS Gateway using 12.05(T)
c. MC3810 Cisco IOS Gateway using 12.05(T)
d. A, B, and C
e. A and B
f. B and C
g. A and C
8)
Consider this scenario. You have two branch offices using IP telephony with CallManager 2.4. To handle

admissions control between the two offices
over a WAN, which of the following solutions will work?
• Solution A: Use a central CallManager (perhaps redundant CallManagers) with each office being a separate
region. Intra-region calls can be G.711, but inter-region calls can be G.729 (unless to voice
mail). Limit WAN
bandwidth at each egress point and block calls that will exceed that level.
• Solution B: Put a CallManager in each location and network them together using H.323 (running on a Cisco
IOS gatekeeper). You can then use the zone bandwidth feat
ure to limit the number of calls and force overflow
to the Public Switched Telephone Network (PSTN).

a. Solution A
b. Solution B
c. Either A or B
d. Neither A nor B
9)
Applications using this ATM service category should be tolerant of higher delays and delay variations.
a. Constant bit rate (CBR)
b. Real-time variable bit rate (VBR-RT)
c. Non-real-time VBR (VBR-NRT)
d. Available bit rate (ABR)
10)
In carrying Voice over Data, how is voice quality affected by tandem switching?
a. It improves
b. It stays the same
c. It degrades
11)
With the current Cisco IP Phone, if you lose power locally you lose the phone.
a. True
b. False

12)
Which of the following statements are true about Voice over Frame Relay services?
a. Primary payload types may include voice, fax, or data
b. Signaled payload types may include dialed digits, silence information, or CAS ABCD bits
c. Management payload types include faults and performance measurements
d. A and B
e. B and C
f. A and C
g. A, B and C
13)
If a legacy voice mail system has an SMDI interface, CallManager can connect to it as a virtual PBX.
a. True
b. False
14)
The only standards-based signaling between a PBX and voicemail is _____.
a. Simplified Messaging Desk Interface (SMDI)
b. TAPI
c. Analog Messaging Indication System (AMIS)
d. SGCP
15)
Which of the following is not a benefit of Simple Gateway Control Protocol (SGCP)?
a. Emphasis on a simple and reliable protocol
b. End points can be mass produced cheaply
c. Smaller set of instructions at the client end mean lower CPU and memory requirements
d. Large set of instructions provide intelligence in endpoint
16)
For capacity planning purposes, plan for G.711 traffic to require ___ through a Cisco router (uncompressed
RTP header and excluding link
-layer header).
a. 80 kbps

b. 24 kbps
c. 17 kbps
d. 74.6 kbps
17)
Leaving or retrieving a message under the uOne architecture involves which of the following protocols:
a. SMTP
b. Lightweight Directory Access Protocol (LDAP)
c. Cisco Skinny
d. All the above
e. None of the above
18)
Cisco supports and is certified with the Lucent Octel 250 and 350 for CallManager 2.x.
a. True
b. False
19)
H.323 signaling:
a. Follows a peer-to-peer model
b. Follows a client-server model
20)
With CallManager 2.x, a distributed CallManager design requires the use of an MTP with each CallManager.
You are then required to use which CODEC?

a. G.723
b. G.729a or G.729b
c. G.711
d. G.728
21)
The ITU specifies the threshold for high quality voice as an end-to-end delay of:
a. 100 ms
b. 150 ms

c. 200 ms
d. 250 ms
22)
Which of the following elements are typically part of a legacy PBX's implementation of a dial plan?
a. First digit table
b. Route list
c. Local number table
d. Class of service table
e. All of the above
f. None of the above
23)
Which of the following is not included in the H.323 protocol?
a. Quality of service (QoS)
b. Voice coding
c. Video coding
d. Signaling
24)
Which of these statements are true about the IP WAN with centralized call processing using CallManager 2.4?

a. All local gateway access codes must be different
b. Conferencing and voice mail must use G.711
c. Phones are out of service if the WAN goes down unless there is dial backup
d. All the above
e. A and B only
25)
Low-speed links require link fragmentation and interleaving at Layer 2 (similar to MLPPP or FRF.12) for
circuits running slower than 768 kbps. Which of the following is a valid workaround?

a. Use two PVCs, one for voice and one for data
b. IP MTU reduction

c. Either, with caveat
d. Neither, in any case
26)
In implementing Voice over Data networks, in all likelihood you will be able to use the le
gacy dial plan without
any changes.

a. True
b. False
27)
CallManager 3.0 will support MGCP, which allows for Cisco IOS gateway and CallManager integration
without an MT
P.
a. True
b. False
28)
T1 and E1 trunk signaling can be either CAS or CCS.
a. True
b. False
29)
For IP Telephony the recommended admissions control tool is:
a. RSVP
b. Manual intervention using access lists
c. Appropriate network deployment following known success guidelines
30)
Which of the following statements is not a characteristic of FRF.11?
a. It provides application support for compressed voice
b. It provides multiplexing of up to 255 subchannels
c. It allows multiple payloads
d. It uses a predictable fixed length payload

31)
Which of the following elements requires minimizing to provide voice quality in packet or cell networks?
a. Loss
b. Delay/Delay Variation
c. Echo
d. A, B, and C
e. A and B
f. B and C
g. A and C
32)
This IP Telephony component plays dial tone.
a. CallManager
b. MTP
c. uOne
d. IP Phone
e. Gateway
33)
The _____________ low bit-rate coder requires less CPU power, while maintaining high voice quality, thus
enabling support for two voice calls on a single DSP.

a. G.711
b. G.729
c. G.729a
d. G.723
34)
Consider this scenario. You want to transparently emulate a T1 or E1 for transport across an ATM network, so
that you can replace a point
-to-point circuit that carries a proprietary
PBX
-to-PBX protocol. Which service would you use?

a. T1/E1 CES unstructured
b. T1/E1 CES structured
c. FRF.12
d. MLPPP
35)

You are planning for an IP Telephony deployment including the deployment of CallManager in a branch office.
Which of these factors should
you consider as you assess the customer's existing branch office voice and data
networks?

a. Are firewalls present on any LAN where Voice over IP traffic would travel?
b. Are the available ports switched or on hubs?
c. Does the customer require an MWI for voice mail messages?
d. What protocol or signaling is used between handset and PBX for the existing PBX?
e. A, B, C, and D
f. A and B
g. A, B and C
h. A and C
36)
Cisco's uOne is a standards-
based messaging application that manages message playback, message delivery, and
the message creation process in CallManager 2.4 deployments.

a. True
b. False
37)
The CallManager database uses _________ to tie an actual IP Phone to a telephone number.
a. Media Access Control (MAC) address
b. Directory Number

c. Line Appearance Number
d. IP Address
38)
In ATM while a typical voice payload takes only 20 bytes of a 48-
byte payload resulting in 28 bytes of padding,
efficiency is gained b
ecause the predictable fixed-length cells allow highly efficient switching that can be built into
chip design.

a. True
b. False
39)
System assurance is a key part of the planning stage of design methodology, because:
a. It ensures that a network foundation exists on which voice applications can be built
b. It ensures that an existing network can handle voice traffic reliably
c. It provides the necessary information to perform capacity planning
d. A, B, and C
e. A and B
f. B and C
g. A and C
40)
In designs involving tie-line replacement and toll bypass solutions, voice mail considerations will not impact
your design since voice mai
l will typically be carried via the PSTN to the PBX.
a. True
b. False
41)
The manual attendant console for CallManager is a Web-based software console.
a. True
b. False

42)
To complete a traffic analysis and thereby plan for sufficient bandwidth on the converged data network, it is
mandatory that you conduct a detailed traffic enginee
ring study and calculate trunk requirements from rate, blocking
and Erlang
-B tables.
a. True
b. False
43)
Lucent's DCS protocol provides ____ voice channels on a T1.
a. 21
b. 22
c. 23
d. 24
44)
Which of the following is a variable source of delay in voice networks:
a. Queuing delay
b. Propagation delay
c. Serialization delay
d. Coder processing delay
45)
If the maximum acceptable delay that a low-speed link may add to your delay budget is 20 ms and the link
speed is 64 kbps, then the maximum fragment size should be ____ bytes.

a. 80
b. 140
c. 160
d. 320
46)
Loop start signaling may be associated with either the station side or the Central Office side of PBX interfaces

.
a. True
b. False
47)
Calculate the approximate bandwidth for G.729 payload using a 20-ms voice sample that generates a 50-pps
stream. Assume a 7
-byte header. The effective bandwidth required per call is approximately:
a. 8.0 kbps
b. 10.8 kbps
c. 32.0 kbps
d. 67.0 kbps
48)
The design recommendation for queuing is:
a. CBWFQ instead of weighted fair queuing (WFQ)
b. IP RTP Priority for Voice over IP
c. RSVP in all cases
d. A and B
e. B and C
f. A and C
49)
Which of the following statements are true about quality of service (QoS) using an ATM network.
a. End-to-end QoS is available in the ATM network by contracting for the services needed to
insure the voice quality required
b. Priority queuing and traffic shaping may still be needed in the end systems
c. Both
d. Neither
50)
Frame forwarding requires that the PBX provide voice signaling through a separate interface from the voice
channels.

a. True
b. False
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