Prove that the Internet checksum computation shown in the text is independent of byte order (host order or network order) except that the bytes in the final checksum should be swapped later to be in the correct order. Specifically, show that the sum of 16-bit words can be computed in either byte order. For example, if the one's complement sum (denoted by +') of 16-bit words is represented as follows, [A,B] +' [C,D] +' . .. +' [Y,Z] the following swapped sum is the same as the original sum above: [B,A] +' [D,C] +' ... +' [Z,Y]

Prove that the Internet checksum computation shown in the text is independent of byte order (host order or network order) except that the bytes in the final checksum should be swapped later to be in the correct order. Specifically, show that the sum of 16-bit words can be computed in either byte order. For example, if the one's complement sum (denoted by +') of 16-bit words is represented as follows, [A,B] +' [C,D] +' . .. +' [Y,Z] the following swapped sum is the same as the original sum above: [B,A] +' [D,C] +' ... +' [Z,Y]

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

See similar textbooks

Similar questions

Show Steps Please 5. Compute the Hamming distance of the following code: 0011010010111100 0000011110001111 0010010110101101 0001011010011110 6. Suppose we are given the following subset of codewords, created for a 7-bit memory word with one parity bit: 11100110, 00001000, 10101011, and 11111110. Does this code use even or odd parity? Explain. 7. Given that the ASCII code for A is 1000001, what is the ASCII code for J? b. Given that the EBCDIC code for A is 1100 0001, what is the EBCDIC code for J? 8. Decode the following ASCII message, assuming 7-bit ASCII characters and no parity: 1001010 1001111 1001000 1001110 0100000 1000100 1001111 1000101
Suppose we are given the following subset of code words,created for a 7-bit memory word with one parity bit: 11100110,00001000, 10101011, and 11111110. Does this code use even or oddparity? Explain.
1. Compact discs record two channels (left and right) of music at a sampling frequency of ??=44.1kHz for each channel. If each sample is encoded with 16 bits, and one byte is 8 bits, how many bytes are required to store 48.1 seconds of music? 2. Consider a system that uses 8-bit ASCII codes to encode letters. How long (in microseconds) will it take to transmit the bit sequence encoding Hello-World! if we use a bit time of 4 samples per bit, and transmit samples at a rate of 1MHz? 3. The ASCII table below gives the ASCII codes for common alphanumeric characters and symbols listed from MSB to LSB. What is the bit sequence encoding the message 113? Assume that we transmit the codes of each character in sequence with the LSB first.
Consider a SEC code that protects 8 bit words with 4 parity bits. If we read the value 0x375, is there an error? If so, correct the error.
Suppose you have a 4-letter alphabet {A, B, C, D} and you wish to devise a binary code (with nospaces) for this alphabet such that no two words would be encoded the same. For example, if A = 1and B = 11, then AA and B would be encoded the same. It takes one second to transmit eachcharacter of the binary code (so, 101 would take 3 seconds and 110101 would take 6 seconds).(a) If each letter occurs with the same frequency, determine the most efficient code for the alphabetand explain why it is the most efficient.(b) Now suppose letter A occurs about 40% of the time, B and C both occur about 25% of thetime each, and C occurs about 10% of the time. Determine the most efficient code and explainwhy it is the most efficient.
Suppose Data Encryption Standard (DES) is used to encrypt the following 64-bit block ofplaintext:6 3 F A C 0 D 0 3 4 D 9 F 7 9 3Given the initial 64-bit key is: 1 C 5 8 7 F 1 C 1 3 9 2 4 F E F(1) Derive the first-round subkey, K1, representing in both binary and hexadecimal. (2) Derive left and right parts of the plaintext, L0, R0, representing in both binary andhexadecimal. (3) Expand R0 to get E[R0]. (4) Calculate A= E[R0] XOR K1, representing in both binary and hexadecimal. (5) Group the 48-bit results of (4) into sets of 6 bits and evaluate the corresponding S-boxsubstitutions, representing in both binary and hexadecimal.
Given a positive integer, check whether it has alternating bits: namely,if two adjacent bits will always have different values.For example:Input: 5Output: True because the binary representation of 5 is: 101.Input: 7Output: False because the binary representation of 7 is: 111.Input: 11Output: False because the binary representation of 11 is: 1011.Input: 10Output: True because The binary representation of 10 is: 1010.""" # Time Complexity - O(number of bits in n)def has_alternative_bit(n): first_bit = 0 second_bit = 0 while n: first_bit = n & 1 if n >> 1: second_bit = (n >> 1) & 1 if not first_bit ^ second_bit: return False else: return True n = n >> 1 return True # Time Complexity - O(1)def has_alternative_bit_fast(n): mask1 = int('aaaaaaaa', 16) # for bits ending with zero (...1010) mask2 = int('55555555',.
Suppose we are working with an error-correcting code that will allow all single-bit errors to be corrected for memory words of length 7. We have already calculated that we need 4 check bits, and the length of all code words will be 11. Code words are created according to the Hamming algorithm presented in the text. We now receive the following code word: 1 0 1 0 1 0 1 0 1 1 0 Assuming odd parity, is this a legal code word? If not, according to our error-correcting code, where is the error?
Please explain step by step:Let e = 2.71828183 be the Euler’s number with 8 decimal digits of precision.Find the binary scientific notation of e with five bits after the binary point; i.e. find integer n and bits x1, x2, . . . , x5 such that e = 1.x1x2x3x4x5 × 2 n .Find the single-precision IEEE 754 representation of e. (Hint: Round the result of 223e to the closest integer like m. Convert m to its normalized binary scientific notation and round its fraction to 23 bits after the binary point. Finally, find the normalized binary scientific notation of m/2 23 by subtracting 23 from the power of two in the representation of m).
Consider the Cyclic Redundancy Check (CRC) algorithm discussed in Section 6.2.3 of the textbook. Suppose that the 4-bit generator (G) is 1011, that the data payload (D) is 10011101 and that r = 3. What are the CRC bits (R) associated with the data payload D, given that r = 3?
What is the worst case efficiency for a path compression algorithm?a) O(N)b) O(log N)c) O(N log N)d) O(M log N)
If we use the 128-bit binary field extension F 128 to decode the 127-bit binary BCH code at a distance of 6, we get a total of 127 bits. How big is the code, and is there a guaranteed minimum separation?