CCNA 3 Chapter 7 V4.0

Note: These answers will give you a 76.2%. Please correct any answers you think are wrong

Which two statements describe the function of time-division multiplexing? (Choose two.)
Multiple data streams share one common channel.
Conversations that require extra bandwidth receive any unused time slices. ******
Time slots are utilized on a first-come, first-served basis. *****
Packets that are sent during transmission are reconstructed at the receiving end.
Priority can be dedicated to one data source.

At which two layers of the OSI model does a WAN operate? (Choose two.)
Layer 1 ****
Layer 2 ****
Layer 3
Layer 4
Layer 6
Layer 7

Which three statements describe functions of the Point-to-Point Protocol with regards to the OSI model? (Choose three.)
operates at all layers of the OSI model
provides a mechanism to multiplex several network layer protocols ****
can be configured on both synchronous and asynchronous serial interfaces *****
uses Layer 3 of the OSI model to establish and maintain a session between devices
uses the data link layer to configure such options as error detection and compression *****
uses network control protocols to test and maintain connectivity between devices

When customers use credit cards to make purchases at a small business, a modem is heard dialing a telephone number to transfer the transaction data to the central office. What type of WAN serial connection is in use?
leased line
circuit switched *****
packet switched

Permanent virtual circuits and switched virtual circuits are both part of which option for WAN connectivity?
leased line
cell switching
packet switching
circuit switching ****

Which two options can LCP negotiate? (Choose two.)
link quality ****
authentication *****
dynamic flow control
compression and network layer address for IP
connection-oriented or connectionless communication methods

Why are Network Control Protocols used in PPP?
to establish and terminate data links
to provide authentication capabilities to PPP
to manage network congestion and to allow quality testing of the link
to allow multiple Layer 3 protocols to operate over the same physical link *****


Refer to the exhibit. What statement is true about the debug output?
R2 is using PAP instead of CHAP.
The routers have different CHAP passwords configured. *****
The administrator performed a shutdown on the R2 PPP interface during negotiation.
The Layer 3 protocol negotiation caused the connection failure.

Which best describes data communications equipment (DCE)?
serves as data source and/or destination
responsible for negotiating windowing and acknowledgements
physical devices such as protocol translators and multiplexers
equipment that forwards data and is responsible for the clocking signal ****

What statement best describes cell switching?
dedicated path created between endpoints
permanent physical link between two points
virtual circuits established in network of ISPs
fixed-length packets that traverse virtual circuits ****

What is the data transmission rate for the DS0 standard?
56 kbps
64 kbps ****
1.544 Mbps
44.736 Mbps

What best describes the use of a data-link connection identifier (DLCI)?
an address identifying a virtual circuit *****
a logical address identifying the DCE device
an address identifying a Layer 3 service across a Frame Relay network
a logical address identifying the physical interface between a router and a Frame Relay switch

At what physical location does the responsibilty for a WAN connection change from the user to the service provider?
demilitarized zone (DMZ)
demarcation point *****
local loop

Which three statements are true regarding LCP? (Choose three.)
It is responsible for negotiating link establishment.
It negotiates options for Layer 3 protocols running over PPP. ****
It uses MD5 encryption while negotiating link-establishment parameters. ****
It terminates the link upon user request or the expiration of an inactivity timer.
It can test the link to determine if link quality is sufficient to bring up the link. ****
It monitors the link for congestion and dynamically adjusts the acceptable window size.


Refer to the exhibit. What statement is true regarding the output shown?
LCP is in the process of negotiating a link.
LCP and NCP are waiting for CHAP authentication to complete.
LCP negotiation has completed successfully, but NCP negotiation is in progress. *****
LCP and NCP negotiation is complete, and the data link service is available to carry packets.

Refer to the exhibit. The command output is from two routers that are connected by a point-to-point T1 link. Based on the information shown, what is the likely problem if the routers are unable to communicate using TCP/IP?
A loopback has not been set on either router.
The routers have mismatched serial line encapsulation. *****
Carrier delay has not been configured on router Cisco_2801.
The IP addresses are not in the same subnet.

Why are Frame Relay paths referred to as virtual?
Frame Relay PVCs are created and discarded on demand.
The connections between PVC endpoints act like dialup circuits.
There are no dedicated circuits to and from the Frame Relay carrier.
The physical circuits inside the Frame Relay cloud do not contain exclusive links for a specific Frame Relay connection. ****

What does a Frame Relay switch use to inform the sender that there is congestion?
FECN ****

Which statement is true concerning the Cisco implementation of the HDLC protocol?
supports authentication
universally compatible frame format
default encapsulation for serial interfaces on Cisco routers *****
does not support multiple protocols across a single link

What two services allow the router to dynamically map data link layer addresses to network layer addresses in a Frame Relay network? (Choose two.)
Proxy ARP
Inverse ARP ****
LMI status messages****