::Cisco CCNA 4[Ver 3.1]::Module 02::

[Posted by Alice]

[Special Instructions: All things are given step by step. * mark means the answer(s). If you think some answers are wrong then give your comment or mail to RecentCCNAComment@gmail.com]

1 Which statement is true regarding WAN technologies?
Most WANS use only one technology throughout the infrastructure such as ISDN, Frame Relay or ATM.
Data transfer speeds on the WAN are typically faster than the speeds on a LAN.
*WANs operate at the lower three layers of the OSI model.
WANs are unable to support the transfer of voice or video traffic.

2 Which of the following are disadvantages of circuit-switched networks? (Choose two.)
Data is subject to unpredictable delays while it waits for other subscribers to transmit data.
* The connection capacity is used inefficiently due to irregular traffic bursts.
Data delivery is less reliable because only connectionless delivery methods are used.
* Circuit-switched networks are more expensive for data traffic.
Circuit-switched networks are less expensive for 24/7 data traffic.

3 A company requires a WAN connection that will carry 64 kbps and allow fast call setup time. The connection does not need to carry video. What is the best choice for this company?
ATM
ISDN BRI
X.25
* analog dialup

4 Which of the following is commonly used as Data Terminal Equipment?
ISDN
* modem
router
CSU/DSU

5 Why is it important to identify the type of traffic that will be carried on the WAN links before choosing a WAN technology?
to determine the routing protocol to be used on the WAN link
to determine the WAN topology
* to determine the requirements for latency and jitter
to determine the type of signaling protocol to be used on the WAN link

6 On which of the following are most Layer 2 WAN encapsulations based?
IP
PPP
* HDLC
SLIP
HSSI
CSU

7 Which term describes the cabling that connects the customer site to the nearest exchange of the WAN service provider?
CPE
CO
* local loop
DCE
DTE

8 A European company needs a low cost, dialup WAN connection to validate transactions for point-of-sale card readers. Which connection type is commonly used for this situation?
ATM
* X.25
Frame Relay
Leased lines

9 Which of the following describes a packet-switched network using connection-oriented data transfer? (Choose two.)
* Each packet carries an identifier.
Each packet carries full addressing information.
Each switch in the route must evaluate the addressing information to determine where to send the packet.
* Each switch determines where to send the packet by examining tables in memory.
The addressing information is used to set switches along the route of data transfer to create a continuous copper circuit.

10 A large company already has a T1 leased line but this connection is inadequate at peak business hours. Furthermore, they would like a backup WAN connection in case their leased line temporarily fails. What type of WAN connection is commonly used in this situation?
X.25
DSL
* ISDN
cable modem
56 kbps

11 Depending on the company size and geographical layout, there might be many end points on the company WAN. Why is it important to identify all the end points of the WAN before choosing a WAN design?
to determine the routing protocol to be used on the WAN link
* to determine the WAN topology
to determine the requirements for latency and jitter
to determine the signaling protocol to be used on the WAN link

12 A new international company needs to have a design for WAN connectivity. The company will have at least five offices in every state in the United States and Mexico. Some states will have as many as 20 offices. The branch offices will require constant contact with the services of the main office. Which design model is best for WAN connectivity in this situation?
a mesh network of all branch WANs
a simple star topology connecting all branch LANs to a central router with multiple interfaces
a one layer design using Frame Relay links between LANs
* a three layer hierarchical topology interconnecting branch LANs within an area, the area LANs within a region, and connecting the regions to form the core of the WAN

13 Which statements are correct regarding ATM connections? (Choose two.)
uses only PVCs
* is useful for video transfers
* has data rates beyond 155 Mbps
cells have 32 byte payload and a 5 byte overhead
mandates single virtual circuits on a single leased line connection

14 Which of the following is true of WANs?
Shared network WAN technologies such as Frame Relay and ATM are more expensive but offer less latency and jitter than dedicated lines.
ISDN is suitable for large enterprises.
* The more network devices that data has to pass through across the WAN, the more latency and less reliability the network will experience.
WANs typically incorporate only one technology such as ISDN, Frame Relay, or ATM.

15 Which of the following connections will provide the equivalent of a T1/E1 connection and is intended for large businesses?
BRI
* PRI
DLCI
PSTN
POTS

16 A company only requires a WAN connection to transfer sales data from individual stores to the home office. All transfers will occur after business hours. They estimate they will never need a connection faster than 56 kbps. Which type of connection is best for this company?
ATM
ISDN
* analog dialup
T1 Leased Line

17 Which of the statements regarding DSL are correct? (Choose three.)
DSL provides a consistent bandwidth of 2.154 Mbps.
DSL connections provide a fast dialup to establish a WAN connection.
* DSL connects the local loop to a digital subscriber line access multiplexer.
* DSL bandwidth varies and can exceed the bandwidth of a T1/E1 leased line.
* For DSL to function properly, the local loop must be less than 5.5 kilometers (3.5 miles).
DSL is a popular choice for enterprises that need to connect home users to the local network due to strong security.