Dont dont dont dont post copied content sure strict action skip if dont know A new architecture, with N layers, is proposed. User application at the top layer generates a message of Mbytes. At each layer, an H bytes header is added. The second layer of that architecture also adds T bytes trailer.In this architecture, the message M is not divided into smaller packets at any layer.• What is the size of the final message (in bytes) transferred by the lower layer?• If we consider the headers and trailers to be an overhead, what is the percentage of such overhead tothe total size of the final message?

A new architecture, with N layers, is proposed. User application at the top layer generates a message of M bytes. At each layer, an H bytes header is added. The second layer of that architecture also adds T bytes traile

A new architecture, with N layers, is proposed. User application at the top layer generates a message of M bytes. At each layer, an H bytes header is added. The second layer of that architecture also adds T bytes traile

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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In modern packet-switched networks, including the Internet, the source host segments long, application-layer messages (for example, an image or a music file) into smaller packets and sends the packets into the network. The receiver then reassembles the packets back into the original message. We refer to this process as message segmentation. Figure 1.27 illustrates the end-to-end transport of a message with and without message segmentation. Consider a message that is 8. 106 bits long that is to be sent from source to destination in Figure 1.27. Suppose each link in the figure is 2 Mbps. Ignore propagation, queuing, and processing delays. a. Consider sending the message from source to destination without message segmentation. How long does it take to move the message from the source host to the first packet switch? Keeping in mind that each switch uses store-and-forward packet switching, what is the total time to move the message from source host to destination host? b. Now suppose that…
In a bit-oriented link-layer protocol, the start and end of a frame are each marked by a flag, which is a sequence of exactly 6 consecutive 1 bits. Bit stuffing is used during the rest of the frame: after sending 5 consecutive 1 bits, a 0 is added. The bits below contain an example frame, with the leftmost bit received first. The content of the frame is a sequence of bytes, sent most significant bit first. Put the values of the first four bytes of the frame content, in order, in the four answer boxes below. You may enter the values in either decimal (e.g. 76, 123) or hexadecimal (e.g. 2a, f7). 00101011111010001111110011100111110000111101111101010110100010010011111101101100100 57−240−123−229
A frame containing http request is sent from Computer (A) [in whichever subnet it is now, make sure to show it in your figure], to the access point it is associated with. Draw the address fields (1, 2, and 3) of the frame travelling from Computer A to AP and the source and destination addresses of the frame travelling from AP to R1. The MAC addresses of AP1, AP2, and AP3 are M1, M2, and M3 respectively, and the Router R1’s MAC address connected to this Switch/AP is MRA. IP address values are already given, and the port addresses could also be used as given. The Router’s MAC address facing WAN side is MRW.
Suppose you are hired to design a reliable byte-stream protocol that uses a sliding window (like TCP). This protocol will run over a 50-Mbps network, the RTT of the network is 80 ms and the maximum segment lifetime is 60 seconds. How many bits would you include in the Advertised Window and Sequence Num fields of your protocol header?
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We compress the video with the pattern GoP (16 : 3) by using MPEG coding. Assume that the average compression ratios of frame I, frame P, and frame B are 1:5, 1:20, and 1:60, respectively. We put the compressed frames in 512 B packets and send them. The header size of each packet is 5% of the size of packet. Each packet contains information on one frame and its header, Each frame can be sent in multiple packets. Picture resolution is 196 × 144 for a video at 32 fps. (a)What is the compression ratio in this pattern? (b)What is the order of coding and transmitting frames in this pattern? (c)If frame 6 is lost while transmission, which frames will be faulty? (d)If frame 5 is lost while transmission, which frames will be faulty? (e)If frame 17 is lost while transmission, which frames will be faulty? (f)Find the size of uncompressed image frame? (g)In how many packets can an I-frame be transmitted on average? (h)In how many packets can an I-frame be transmitted on average? (i)In how many…
Consider a simple protocol for transferring files over a link. After some initial negotiation, A sends data packets of size 1 KB to B; B then replies with an acknowledgment. A always waits for each ACK before sending the next data packet; this is known as stop-and-wait. Packets that are overdue are presumed lost and are retransmitted. (a) In the absence of any packet losses or duplications, explain why it is not necessary to include any "sequence number" data in the packet headers. (b) Suppose that the link can lose occasional packets, but that packets that do arrive always arrive in the order sent. Is a 2-bit sequence number (that is, N mod 4) enough for A and B to detect and resend any lost packets? Is a 1-bit sequence number enough? (c) Now suppose that the link can deliver out of order and that sometimes a packet can be delivered as much as 1 minute after subsequent packets. How does this change the sequence number requirements?
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When we encode a signal (a stream of bits) in the physical layer, we convert the bits into different voltage levels. We have a choice of the signal level range, and how many different levels to use, but all communicating nodes must agree on the encoding scheme so that they may properly decode the signal later. For example, we might encode values as either 0 volts (OV) or 5 volts (5V), therefore using two signal levels. We might encode 0V, 10V, 20V, 30V, 40V, 50V and have six signal levels. There is no "correct" choice of encoding scheme for all situations. a) How would the distance of a link affect this decision? (The physical distance between two communicating machines which are using the same encoding scheme) b) In what way might cost be an issue when deciding the scheme? Edit View Insert Format
When we encode a signal (a stream of bits) in the physical layer, we convert the bits into different voltage levels. We have a choice of the signal level range, and how many different levels to use, but all communicating nodes must agree on the encoding scheme so that they may properly decode the signal later. For example, we might encode values as either 0 volts (OV) or 5 volts (5V), therefore using two signal levels. We might encode 0V, 10V, 20V, 30V, 40V, 50V and have six signal levels. There is no "correct" choice of encoding scheme for all situations. a) How would the distance of a link affect this decision? (The physical distance between two communicating machines which are using the same encoding scheme) b) In what way might cost be an issue when deciding the scheme?
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