Braindumps of 920-803
Technology Standards and Protocol
For IP Telephony Solutions
Exam Questions, Answers, Braindumps (920-803)
Thanks to www.exams.ws and www.4exam.com But there’s
no need to have it from both of them, only questions
from only one are sufficient I think.
A customer named Abc .com wants to implementVoIPon
their LAN. What is the role of the gatekeeper in an
A.It converts media formats between divergent networks.
B.It performs address translation and bandwidth management
C.It connects divergent networks by translating between
signaling protocols for call setup and teardown.
D.It supports Internet Telephones with controller
software acting as a Private Branch Exchange (PBX)
to provide feature capabilities, and call setup through
the use of a SIP INVITE to connect a call.
VoIPrequires an IP network to provide the following?
Which network devices should be deployed to achieve
the "best" voice performance?
A.Layer 2/Layer 3 switches with 802.1q tagging enabled
at the core network and managed hubs at the network
B.Requires with filters at the network core and Layer
2 switches with Virtual LANs (VLANs) at the network
C.Layer 2 switches at the core network with Differentiated
Service (DiffServ) enabled and routerstih802.1p Class
of Service (CoS) enabled at the network edge.
D.Layer 3 switches at the network core with DiffServ
enabled and Layer 2 switches with 802.1p CoSenabled
at the network edge.
In an H.323 network the gatekeeper and the gateway
work together to manage the interface between theVoIPnetwork
and the Public Switched Telephone Network (PSTN.)
Which two functions does the gatekeeper perform? (Choose
A.determines call type
B.manages call routing
C.handles the dialing plan
D.manages the Call Detail Reporting (CDR)
Answer: B C
Given the following customer network information:
? The IP clients are located on a private network
of 10.168.254.0/24 (site A) using many-to-one, port-basedNetworkAddressTranslation
? The H.323 gateway is located on the public network
at 220.127.116.11 (site B) at a different location.
? The customer network between the IP clients and
the H.323 gateway appears to be set up properly because
you can ping form site A to site B A customer named
Abc .com is complaining of a one-way speech path in
this setup when calling from an IP client to the H.323
gateway. What is the most likely cause of this issue?
A.The IP clients on the private network need a gatekeeper
on the private network to place calls to the H.323
gateway on the public network.
B.The IP clients on the private network need a media
gateway on the public network to place calls to the
H.323 gateway on the public network.
C.The H.323 gateway on the public network needs a
media gateway on the private network to transcode
the calls to the IP clients on the private network.
D.The IP clients on the private network use private
addresses mapped to a single public address. The media
path from the public address CANNOT reach the IP clients
with the private address.
A customer named Abc .com wants to implementViOPon
their LAN. Which two network devices should be used
to avoid network congestion? (Choose two.)
C.Layer 2 switches
D.Layer 3 switches
E.Shared-media Ethernet hubs
Answer: C D
A customer named Abc .com implementsViOPon their LAN/WAN.
In this network, routers and switches prioritizeVoIPpackets
ahead of other IP data packets end-to-end. Why is
this feature important?
A.It controls jitter.
B.It sets dead lock.
C.It sets rate limits.
D.It controls link bandwidth
In a Layer 3 IP LAN/WAN environment, which method
provides the best control for managing applications
with different types of QoS behaviors?
B.platform queuing controls.
C.Differentiated Services (DiffServ)
D.Internet Protocol (IP) fragmentation
E.Point-to-Point Protocol (PPP) fragmentation
A customer named Abc .com wants to useVoIPon their
LAN. They have deployed several H.323 endpoints. Which
component is responsible for call control, media access,
and bandwidth management between endpoints?
When a call is placed from an H.323 endpoint to another
H.323 endpoint via an IP network, what is the function
of the H.323 gatekeeper?
A.It maps the originating gateway IP address to destination
gateway IP address.
B.It maps the originating telephone number to the
originating gateway IP address.
C.It maps the destination telephone number to the
destination gateway IP address.
D.It maps the destination telephone number to the
destination endpoint IP address.
Which twoCODECshave the least delay (processing or
algorithmic)? (Choose two.)
Answer: A C
The basic attributes of Real-Time Protocol (RTP) provide
for support of applications like voice and video.
Which three attributes of RTP support real-time applications?
Answer: A B D
Atributtesread for RTP:1.Timestamping2.Payload Identification3.Sequency
Which CODEC is the most tolerant to network delay?
What are two differences between IP, Asynchronous
Transfer Mode (ATM) and Frame Relay (FR)? (Choose
A.ATM has a fixed cell size, but IP and FR do NOT.
B.FR has built in mechanisms within the protocol for
C.ATM is connectionless, but IP and FR are connection
D.IP is a Layer 3 protocol, but ATM and FR are Layer
Answer: A D
A video conference is in progress between two networked
locations using gigabit Ethernet. The video conferencing
application is using User Datagram Protocol (UDP)
to transport the video and audio data. Why should
UDP be used instead of Transmission Control Protocol
A.TCP CANNOT handle streaming data applications.
B.UDP is better than TCP at seamlessly synchronizing
voice and video together.
C.UDP serves as an efficient transport for handling
real-time application traffic.
D.UDP uses less bandwidth than TCP in a WAN, but more
bandwidth than TCP in a LAN.
To implementVoIPon a customer's IP network, which
transport protocol should you use to best meet the
real-time requirement for VoIP, and why?
A. User Datagram Protocol (UDP); it ignores lost packets.
B. Transmission Control Protocol (TCP);Itretransmit
C. User Datagram Protocol(UDP);Theamount of delay
time is bounded.
D. Transmission Control Protocol (TCP); The amount
of delay time is bounded