True/False
Indicate whether the
statement is true or false.
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1.
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All VoIP calls are carried over the Internet.
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2.
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IP telephones are directly connected to the local loop.
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3.
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An off-the-shelf workstation can be programmed to act like an IP
telephone.
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4.
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SIP and H.323 account for communication between media gateways.
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5.
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It is more difficult to transmit VoIP and video over IP signals over a
packet-switched network than it is to transmit data signals.
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Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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____ is the use of one network to simultaneously carry voice, video, and data
communications.
a. | Multicasting | c. | Divergence | b. | Unicasting | d. | Convergence |
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2.
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____ describes the use of any network to carry voice signals using the TCP/IP
protocol.
a. | Telephony | c. | IP telephony | b. | Internet telephony | d. | Voice telephony |
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3.
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When VoIP relies on the Internet, it is often called ____.
a. | telephony | c. | IP telephony | b. | Internet telephony | d. | voice telephony |
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4.
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IPTV, videoconferencing, streaming video, and IP multicasting belong to the
range of services known as ____.
a. | voice over IP | c. | video over IP | b. | data over IP | d. | Web over IP |
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5.
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____ messaging is a service that makes several forms of communication available
from a single user interface.
a. | Unified | c. | Diversified | b. | Instant | d. | Open |
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6.
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Using VoIP over a WAN allows an organization to avoid paying long-distance
telephone charges, a benefit known as ____.
a. | charge bypass | c. | toll bypass | b. | distance bypass | d. | easypass |
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7.
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When using an analog telephone, a VoIP adapter that performs analog-to-digital
conversion is known as a(n) ____.
a. | VTA (voice telephone adapter) | c. | DTA (digital telephone
adapter) | b. | ATA (analog telephone adapter) | d. | DTA (data telephone
adapter) |
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8.
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In general, a(n) ____ is a private switch that accepts and interprets both
analog and digital voice signals.
a. | IP-PBX | c. | Data PBX | b. | analog PBX | d. | IT-PBX |
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9.
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When a caller uses an IP telephone, his or her voice is immediately digitized
and issued from the telephone to the network in ____ form.
a. | segment | c. | circuit | b. | frame | d. | packet |
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10.
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A computer programmed to act like an IP telephone is known as a(n) ____.
a. | video phone | c. | streaming server | b. | softphone | d. | compu-phone |
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11.
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The popular Internet telephony software, Skype, is a type of ____.
a. | IP telephone | c. | teleapplication | b. | softphone | d. | compu-phone |
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12.
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Among all video-over-IP applications, ____is perhaps the simplest.
a. | VoIP | c. | IPTV | b. | videoconferencing | d. | streaming video |
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13.
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One drawback to ____ video is that content may not be edited before it’s
distributed.
a. | on demand | c. | streaming server | b. | live streaming | d. | VoIP |
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14.
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Many streaming video services - and nearly all of those issued over a public
network, such as the Internet - are examples of ____ transmissions.
a. | multicast | c. | unicast | b. | broadcast | d. | telecast |
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15.
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When more than two people participate in a videoconference, for example, in a
point-to-multipoint or multipoint-to-multipoint scenario, a video ____ is required.
a. | bridge | c. | gateway | b. | switch | d. | router |
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16.
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____ signaling functions are more limited than those performed by the protocols
in the H.323 group.
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17.
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SIP and H.323 regulate ____ for VoIP or video-over-IP clients and
servers.
a. | call signaling only | b. | control only | c. | call signaling and
control | d. | communication between media gateways |
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18.
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A(n) ____ is a computer that manages multiple media gateways.
a. | MPLS | c. | MEGACO | b. | MGCP | d. | MGC |
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19.
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Many network engineers consider ____ to be superior to MGCP.
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20.
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____ is preferred over TCP for real-time applications such as telephone
conversations and videoconferencing.
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21.
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____ is a measure of how well a network service matches its expected
performance.
a. | QoS | c. | DiffServ | b. | RSVP | d. | MPLS |
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Completion
Complete each
statement.
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1.
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When streaming videos are supplied via the Web, they are often called
____________________.
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2.
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Some VoIP vendors prefer ____________________ over H.323.
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3.
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____________________ performs the same functions as MGCP, but using different
commands and processes.
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4.
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____________________ is a simple technique that addresses QoS issues by
prioritizing traffic.
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5.
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____________________ is a QoS technique that replaces the IP datagram header
with a label at the first router a data stream encounters.
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Matching
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Match each item with a statement below: a. | H.323 terminal | f. | H.225 | b. | H.323 gateway | g. | H.245 | c. | H.323
gatekeeper | h. | RTP | d. | MCU (multipoint control
unit) | i. | RSVP | e. | H.323 zone |
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1.
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A collection of H.323 terminals, gateways, and MCUs that are managed by a
single H.323 gatekeeper.
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2.
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A device providing translation between network devices running H.323 signaling
protocols and devices running other types of signaling protocols.
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3.
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Helps voice and video networks overcome UDP’s shortcomings.
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4.
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The H.323 protocol that handles call or videoconference signaling.
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5.
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Any node that provides audio, visual, or data information to another
node.
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6.
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Attempts to reserve a specific amount of network resources for a transmission
before the transmission occurs.
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7.
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A computer that provides support for multiple H.323 terminals and manages
communication between them.
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8.
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The nerve center for networks that adhere to H.323.
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9.
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Ensures that the type of information issued to an H.323 terminal is formatted
in a way that the H.323 terminal can interpret.
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Short Answer
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1.
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How does implementing VoIP assist in centralizing voice and data network
management?
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2.
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Describe IP telephones and how they are connected to a network.
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3.
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Explain the issue that IP telephones face regarding the need for electric
current .
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4.
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Aside from extreme mobility, describe another advantage to softphones.
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5.
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Describe six functions performed by signaling protocols.
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6.
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Describe five capabilities to which SIP is limited.
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7.
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Explain how gateways on a converged network exchange and translate signaling and
control information with each other so that voice and video packets are properly routed through the
network.
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8.
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Explain why MGCs are especially advantageous on large VoIP networks.
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9.
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Explain why UDP is preferred over TCP for real-time applications such as
telephone conversations and videoconferences.
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10.
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Describe the RTCP (Real-time Transport Control Protocol), as defined in RFC 3550
by the IETF.
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