Consider a half-duplex point-to-point link using a stop-and-wait scheme, in which a series of messages is sent, with each message segmented into a number of frames. Ignore errors and frame overhead. A. What is the effect on line utilization of increasing the message size so that fewer messages will be required? Other factors remain constant. B. What is the effect on line utilization of increasing the number of frames for a constant message size? C. What is the effect on line utilization of increasing frame size?

Consider a half-duplex point-to-point link using a stop-and-wait scheme, in which a series of messages is sent, with each message segmented into a number of frames. Ignore errors and frame overhead. A. What is the effect on line utilization of increasing the message size so that fewer messages will be required? Other factors remain constant. B. What is the effect on line utilization of increasing the number of frames for a constant message size? C. What is the effect on line utilization of increasing frame size?

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Consider sending a file of F bits over a path of Q links. Each link transmits at R bits per second (bps). The network is lightly loaded so that there are no queueing delays. When a form of packet switching is used, the F bits are broken up into packets, each packet with L bits, of which h bits of it are header. Propagation delay is negligible. Let F = 5x104, Q = 20, R = 1 Mbps, L = 1000, and h = 10. b) Suppose the network is a packet-switched datagram network and a connectionless service is used. How long does it take to send the file?
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Consider a short, 10-meter link, over which a sender can transmit at a rate of 150 bits/sec in both directions. Suppose that packets containing data are 100,000 bits long, and packets containing only control (e.g., ACK or handshaking) are 200 bits long. Assume that N parallel connections each get 1/N of the link bandwidth. Now consider the HTTP protocol, and suppose that each downloaded object is 100 Kbits long, and that the initial downloaded object contains 10 referenced objects from the same sender. Would parallel downloads via parallel instances of non-persistent HTTP make sense in this case? Now consider persistent HTTP. Do you expect significant gains over the non-persistent case? Justify and explain your answer
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One helpful exercise is to weigh the merits of connection-based versus connectionless protocols against one another.