Advertisment

Thứ Sáu, 27 tháng 12, 2013

chapter 4 CCNA 5 routing and switching 2013 /2014

chapter 4 routing & switching V5.0

 
Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media?
  • Data link

Which statement describes signaling at the physical layer?
  • Sending the signals asynchronously means that they are transmitted without a clock signal.

What are two reasons for physical layer protocols to use frame encoding techniques? (Choose two.)
  • to distinguish data bits from control bits
  • to identify where the frame starts and ends

The throughput of a FastEthernet network is 80 Mb/s. The traffic overhead for establishing sessions, acknowledgments, and encapsulation is 15 Mb/s for the same time period. What is the goodput for this network?
  • 65 Mb/s

A network administrator notices that some newly installed Ethernet cabling is carrying corrupt and distorted data signals. The new cabling was installed in the ceiling close to fluorescent lights and electrical equipment. Which two factors may interfere with the copper cabling and result in signal distortion and data corruption? (Choose two.)
  • EMI
  • RFI

How is the magnetic field cancellation effect enhanced in UTP cables?
  • by increasing and varying the number of twists in each wire pair

Refer to the exhibit. What is wrong with the displayed termination?
  • The untwisted length of each wire is too long.

Refer to the exhibit. The PC is connected to the console port of the switch. All the other connections are made through FastEthernet links. Which types of UTP cables can be used to connect the devices?
  • 1 - rollover, 2 - straight-through, 3 - crossover

Which statement is correct about multimode fiber?
  • SC-SC patch cords are used with multimode fiber cables.

What is one advantage of using fiber optic cabling rather than copper cabling?
  • It is able to carry signals much farther than copper cabling.

Why are two strands of fiber used for a single fiber optic connection?
  • They allow for full-duplex connectivity.

A network administrator is designing the layout of a new wireless network. Which three areas of concern should be accounted for when building a wireless network? (Choose three.)
  • Security
  • Interference
  • Coverage Area

A network administrator is required to upgrade wireless access to end users in a building. To provide data rates up to 1.3 Gb/s and still be backward compatible with older devices, which wireless standard should be implemented?
  • 802.11ac

What is one main characteristic of the data link layer?
  • It shields the upper layer protocol from being aware of the physical medium to be used in the communication.

As data travels on the media in a stream of 1s and 0s how does a receiving node identify the beginning and end of a frame?
  • The transmitting node inserts start and stop bits into the frame.

What is true concerning physical and logical topologies?
  • Logical topologies determine the media access control method used.

What are two characteristics of 802.11 wireless networks? (Choose two.)
  • They use CSMA/CA technology.
  • Collisions can exist in the networks.

What is the purpose of the FCS field in a frame?
  • to determine if errors occurred in the transmission and reception

Fill in the blank with a number. 10,000,000,000 b/s can also be written as _____ Gb/s.
  • 10

Fill in the blank. The term _______ indicates the capacity of a medium to carry data and it is typically measured in kilobits per second (kb/s) or megabits per second (Mb/s).
  • bandwidth

Fill in the blank. What acronym is used to reference the data link sublayer that identifies the network layer protocol encapsulated in the frame?
  • LLC

The physical layer encodes the frames and creates the signals that represent the bits. These signals are then sent on the media one at a time. The destination node physical layer retrieves the individual signals from the media, restores them to their bit representations, and passes the bits up to the data link layer as a complete frame.
  • Step 1  -  not scored -
  • Step 2 
  • Step 5 
  • Step 3 
  • Step 4

0 nhận xét:

Đăng nhận xét