RCD1 Lista1b Fund Gab

Lista de Exercícios No 1B
In the following 5 problems, we are sending a 30 Mbit MP3 file from a source host to a destination host. All links in the path between source and destination have a transmission rate of 10 Mbps. Assume that the propagation speed is 2 * 108 meters/sec, and the distance between source and destination is 10,000 km.

1.) Initially suppose there is only one link between source and destination. Also suppose that message switching is used, with the message consisting of the entire MP3 file. The transmission delay is

( ) 50 milliseconds
( ) 3 seconds
( ) 3.05 seconds
( ) none of the above.
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2.) Referring to the above question, the end-to-end delay (transmission delay plus propagation delay) is
( ) 6 seconds
( ) 3.05 seconds
( ) 3 seconds
( ) none of the above
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3.) Referring to the above question, how many bits will the source have transmitted when the first bit arrives at the destination.

( ) 500,000 bits
( ) 30,000,000 bits
( ) 1 bit
( ) none of the above
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4.) Now suppose there are two links between source and destination, with one router connecting the two links. Each link is 5,000 km long. Again suppose the MP3 file is sent as one message. Suppose there is no congestion, so that the message is transmitted onto the second link as soon as the router receives the entire message. The end-to-end delay is
( ) 6.1 seconds
( ) 3.05 seconds
( ) 6.05 seconds
( ) none of the above
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5.) Now suppose that the MP3 file is broken into 3 packets, each of 10 Mbits. Ignore headers that may be added to these packets. Also ignore router processing delays. Assuming store and forward packet switching at the