For the 'Go-Back-N' protocol, which of the following statements about the receiver is FALSE? The receiver uses a checksum to identify corrupted packets None of the mentioned The receiver needs to store all sequence numbers received since the beginning of the transmission The receiver can generate duplicate ACKS The receiver discards out of order packets

For the 'Go-Back-N' protocol, which of the following statements about the receiver is FALSE? The receiver uses a checksum to identify corrupted packets None of the mentioned The receiver needs to store all sequence numbers received since the beginning of the transmission The receiver can generate duplicate ACKS The receiver discards out of order packets

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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A portion of the header of a UDP segment is captured as 8-bit hexadecimal numbers as shown below. 00 35 D2 71 00 86 For this UDP header, the checksum in hexadecimal is Ox[a] and the length of the UDP segment in decimal is [b]. Note: do not include 'Ox' in your first answer.
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?
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
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Please solve it correctly. You receive a packet whose data length is 900 bytes, ID is 2398 and the MF flag is set to 0.You received the remaining 12 packets, each of whose total length is 1945 bytes, ID is 2398and the MF flag is set to 1. All of these packets’ header size is 25 bytes.I. Find the packet size of the original datagramII. Find the value of the offset field of the 2nd last packet [First data byte number starts at0]III. How would you identify the last packet in a group of fragmented packets?
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