Match the words on the left with their definitions on the right.
Date: 2015-10-07; view: 444.
Give all possible derivatives of the following words. Use dictionary if necessary.
To combine, to announce, specific, to separate, to operate, to depend, memory.
6. Write the expansions of the following abbreviations and learn them:
OSI Reference Model, IP, IPX.
| 1. OSI reference model | a.a message-delivery technique in which small units of information (packets) are relayed through stations in a computer network along the best route available between the source and the destination. |
| 2. Layer | b. a collection of stored results that can be accessed very rapidly by a program without the need to calculate each result whenever needed. |
| 3. Packet switching | c. a method of delivering transmissions in which messages are held temporarily by an intermediary before being sent on to their destination. |
| 4. Header | d. a layered architecture (plan) that standardizes levels of service and types of interaction for computers exchanging information through a communications network. |
| 5. Look-up table | e. a network switch that routes packets immediately to the port associated with the packet's recipient. |
| 6. Cut-through switch | f. a temporary storage area for data waiting to be processed. |
| 7. Store-and-forward | g. the protocol or protocols operating at a particular level within a protocol suite, such as IP within the TCP/IP suite. |
| 8.Buffer | h.the portion of a data packet that precedes the body (data). It contains data, such as source and destination addresses and control and timing information that is needed for successful transmission. |
8. Translate the passages in writing:
a)Switches usually work at Layer 2 (Data or Datalink) of the OSI Reference Model, using MAC addresses, while routers work at Layer 3 (Network) with Layer 3 addresses (IP, IPX or Appletalk, depending on which Layer 3 protocols are being used). The algorithm that switches use to decide how to forward packets is different from the algorithms used by routers to forward packets.
b) Broadcasts are used any time a device needs to make an announcement to the rest of the network or is unsure of who the recipient of the information should be. A hub or a switch will pass along any broadcast packets they receive to all the other segments in the broadcast domain, but a router will not.
c) A switch using store-and-forward will save the entire packet to the buffer and check it for CRC errors or other problems before sending. If the packet has an error, it is discarded. Otherwise, the switch looks up the MAC address and sends the packet on to the destination node.
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| EXERCISES | | | Look through parts 7, 8 and 9 of the text and mark the statements as true (T) or false (F). If you think a statement is false, change it to make it true. |