Over Essay

1759 Words Jan 24th, 2012 8 Pages
Michael S Murphy | NET 125
Chapter 7: OSI Data Link Layer
Vocabulary Exercise: Matching Term | Definition | a. Frame | a. Two or more devices connected to a common medium | b. Node | d. A layer of the Open Systems Interconnection (OSI) model that frames upper-layer data and controls how data is placed on a medium | c. Media | b. A device on a network | d. Network | e. The physical means used to carry data signals | e. Data Link | c. The protocol data unit (PDU) used in Layer 2 of the OSI model |

Concept Questions
1. What are the two main jobs of the data link layer? * Allows the upper layers to access the media using techniques such as framing. * Controls how data is placed onto the media and is received from the
…show more content…
Concept Questions
1. Compare and contrast controlled media access control and contention-based media access control.
Although controlled media access is well ordered and provides predictable throughput, these methods can be inefficient because a device has to wait for its turn before it can use the medium. Contention-based media access allows any device to try to access the medium whenever it has data to send.
2. List the steps in the carrier sense multiple access collision detect (CSMA/CD) process. At this point, you can keep the list simple. You will learn more about CSMA/CD in Chapter 9.
In CSMA/CD, the device monitors the media for the presence of data signal.
3. What is the difference between full-duplex communication and half-duplex communication?
Half-duplex communication means that the devices can both transmit and receive on the media but cannot do so simultaneously. In full-duplex communication, both devices can transmit and receive on the media at the same time.
Vocabulary Exercise: Completion
1. A logical multiaccess topology enables a number of nodes to communicate by using the same shared media.
2. Having many nodes share access to the medium requires a data link MAC layer media access control method to regulate the transmission of data.
3. Three media access control methods used by logical multi-access topologies include Header, Data,

Related Documents