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Self-Test 1 Q&A 6-1
Self-Test Questions Volume 1
Question | Answer |
---|---|
What three elements make up a communications system? | A device by which to send a message. A channel or medium over which the message is sent. A device by which to receive the message. |
Compare asynchronous to synchronous transmission. | Asynchronous is either a series of single characters or a block of characters, each character is sent down separately. During synchronous transmission the message block is preceded for the receiving device.The block also is followed for verification. |
What is packet switching? Why is it used? | Transmitting messages in one or more fixed-sized packets, or message blocks. It is used because it provides better use of the network than circuit switching. |
Describe a local area network. | Connection of two or more computers/workstations in a manner that allows users to share files, programs, and data. |
Define physical topology. What should physical topology be based on? | Physical topology refers to how you lay out the different machines or nodes on the network or the physical configuration that the network hardware resembles. Physical topologies should be based on reliability, expandability, and performance. |
Define logical topology. What are the four basic types? | It refers to the method of data transport around the network. It roughly equates to the data link layer of the ISO/OSI reference model. Ethernet, Token Ring, ARCNET, and Fiber Distributed Data Interface. |
Explain Ethernet. | Ethernet has 10 to 100 Mbps throughput and uses a carrier-sensed multiple access with collision detection method to regulate access to the cable. The network interface card (NIC) will listen for any carriers; if none are heard then it will try to transmit |
Explain token ring. | Instead of using collision detection, Token Ring networks use a token-passing scheme to avoid collisions. A free token is passed around the network to each node. When a node wants to transmit, it grabs the token and attaches its packet or frame to it |
Explain Fiber Distributed Data Interface. | Two concentric rings, each operating at 100 Mbps and using token passing in a variation of IEEE 802.5. One ring can be a backup, or the rings can divide the tasks of send and receive, sending in different directions. You can have 1,000 stations networked. |
What is a metropolitan area network? | It is usually made up of multiple LANs. The base network is owned by the communication squadron that interconnects all base LANs. |