COE 431 Problems In Class, Fall 2013

COE 431 Computer Networks Spring 2013 W. FAWAZ Multiple choice questions 1. Suppose there are two links between a source and a destination. The first link has a transmission rate of 100 Mbps and the second link has a transmission rate of 10 Mbps. Assuming that the only traffic in the network comes from the source, what is the throughput for a large file transfer? a. 100 Mbps b. 1 Gbps c. 10 Mbps d. Other (give your answer): 110 Mbps For the following questions, suppose we are sending a 30-Mbit MP3 file from a source host to a destination host. All the links in the path between source and destination have a transmission rate of 10 Mbps. Assume that the propagation speed is 2*10 8 meters/sec, and the distance between source and destination is 10,000 km. Initially suppose there is only one link between the source and the destination. Also suppose that the entire MP3 file is sent as one packet. 1. The transmission delay is: a. 50 milliseconds b. 2.05 seconds c. 4 seconds d. Other (provide your answer): 3 seconds 2. The end-to-end delay is a. 3 seconds b. 2.05 seconds c. 6 seconds d. Other (put your answer): 3.05 seconds 3. How many bits will the source have transmitted when the first bit of the MP3 file arrives at the destination? a. 30,000,000 bits b. 1 bit c. 500,000 bits d. 30,500,000 bits L E B A N E S E A M E R I C A N U N I V E R S I T Y Electrical and Computer Engineering Dept 4. Suppose there are 10 TDM channels in the link. The MP3 file is sent over one of the channels. The end-to-end delay is a. 300 seconds b. 30 seconds c. 300 milliseconds d. Other (give your answer):