The difference between selective repeat and go-back-N is the number of timers it needs tracking. Denote the number of packets sent but not yet ack'eda, the number of packets sent and ack'ed-b, the size of the window N, the number of slots useable but not yet sentc. What is the number of timers that selective repeat needs tracking at any moment?

The difference between selective repeat and go-back-N is the number of timers it needs tracking. Denote the number of packets sent but not yet ack'eda, the number of packets sent and ack'ed-b, the size of the window N, the number of slots useable but not yet sentc. What is the number of timers that selective repeat needs tracking at any moment?

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

Please solve it correctly and please provide explanation of your answers. A PC and a Web Server are communicating over a TCP connection. The PC had started the three way handshake with the initial sequence number of 3069 . The Web Server's initial sequence number is 4830 . The window size of the PC is 815 bytes and the window size of the Web Server is 463 bytes. Using the third TCP handshake ack segment the PC sends the http request of the size 396 bytes to the Web Server. Then the Web Server answers with 3 segments containing the requested data. The first segment size is 42 bytes and the second segment size is 276 bytes and the third segment size is 146 bytes respectively. The PC receives all three segments within the timer. But unfortunately the second segment was corrupted. So the PC immediately sends an acknowledgement segment. Assume that the PC uses Selective Repeat/Reject ARQ. (d) What will be the window size of PC A after receiving only the first segment from webserver? (e)…
We have intercepted a message that we need to decode. Luckily, we know that they use the letters A to Z, space, 0 to 9. We also know that when they encode messages they start by shifting the first letter once to the left, then shift the next twvo letters right twice, then the next three letters left 3 times, then the next four letters right 4 times, the next five letters left 5 times, and so on. a. If the message intercepted was HMMG2WEIAO what was the original message? b. What would we get if we encoded the phrase 2750H FRSC (the Os are zeros) using the given algorithm?
Please solve it correctly and please provide explanation of your answers. A PC and a Web Server are communicating over a TCP connection. The PC had started the three way handshake with the initial sequence number of 3069 . The Web Server's initial sequence number is 4830 . The window size of the PC is 815 bytes and the window size of the Web Server is 463 bytes. Using the third TCP handshake ack segment the PC sends the http request of the size 396 bytes to the Web Server. Then the Web Server answers with 3 segments containing the requested data. The first segment size is 42 bytes and the second segment size is 276 bytes and the third segment size is 146 bytes respectively. The PC receives all three segments within the timer. But unfortunately the second segment was corrupted. So the PC immediately sends an acknowledgement segment. Assume that the PC uses Selective Repeat/Reject ARQ. (a) What will be the sequence number of the third TCP handshake signal send from PC to webserver?…
Q2- You are designing a connection mechanism between two programs, sending packets of data over the internet. You are trying to choose a size for the packets to be sent, depending on the capacity of the channel (channel bandwidth). For example, if a channel has a capacity of 10KB, then you can choose a packet size of 10KB, and send one packet, or choose a packet size of 5KB and send two packets...Etc. The problem you face is that the two programs are at two different locations, with two different channel capacities. If the first channel had a capacity of 3201KB, and the second channel had a capacity of 4565KB, find the maximum packet size that is suitable for both channels.
Computer Networks : Apply the CRC method on given data dividend= 100100 and number of zero’s appended should be 1 less than divisor and divisor in this case is 1101. When there is no error When even numbers of bits are corrupted, highlights the corrupted bits. When odd numbers of bits are corrupted, highlights the corrupted bits.
I am analysing a pcap file using Python and wireshark. Currently, I have it counting the number of packets I would like to count the number of SYN and ACK packets with this function? My main piece of code thus far is n is an int please show me how to write the code for this.
using c++ write a program program:- Suppose that you are receiving a packet number of a data travelling over a network in array. First of all input number of packets a data will be in. Received packets must be in an order and there will be difference of 4 among packet numbers. If there is any missing packet than display message packet missing. If no packets are missing but are not in order arrange the packets in an order.
A common measure of transmission for digital data is the baud rate, defined as the numberof bits transmitted per second. Generally, transmission is accomplished in packets consisting ofa start bit, a byte of information, and a stop bit. Using these facts, answer the following: Write a code for calculating the size of any color image that is defined by the user andfinding transmit time according to the modem that is given by the user.
Prior to the introduction of IEEE 802.11i, the security scheme for IEEE 802.11 was Wired Equivalent Privacy (WEP). WEP assumed all devices in the network share a secret key. The purpose of the authentication scenario is for the STA to prove that it possesses the secret key. Authentication proceeds as shown in Figure 24.13 . The STA sends a message to the AP requesting authentication. The AP issues a challenge, which is a sequence of 128 random bytes, sent as plaintext. The STA encrypts the challenge with the shared key and returns it to the AP. The AP decrypts the incoming value and compares it to the challenge that it sent. If there is a match, the AP confirms that authentication has succeeded.
Description: You are required to implement a server program that responds to both TCP and UDP requests from the corresponding clients. The service provided by the server is simply a substitute cipher/cryptosystem. The cipher replaces one character to another based on some key. The input message (plaintext) can be of any size but composed only of small-letter (abcdefghijklmnopqrstuvwxyz). The output (ciphertext) has the same size and composed also of small-letter characters. The key is limited to 7 characters (also small-letter). You need to treat each digit as a number according to its position in the alphabet. For example, a=0, b=1, …,z=26. To encrypt a message, you add a plaintext character with the corresponding key character (mod 26). The key might be repeated to match the length of the plaintext message. In the decryption, you subtract the corresponding key character from the ciphertext character (mod 26). Again the key might be repeated as necessary. For example, if the…
Suppose you’re consulting for a bank that’s concerned about fraud detection, and they come to youwith the following problem. They have a collection of n bank cards that they’ve confiscated, suspectingthem of being used in fraud. Each bank card is a small plastic object, containing a magnetic stripe withsome encrypted data, and it corresponds to a unique account in the bank. Each account can have manybank cards corresponding to it, and we’ll say that two bank cards are equivalent if they correspond to thesame account.It’s very difficult to read the account number off a bank card directly, but the bank has a high-tech “equivalence tester” that takes two bank cards and, after performing some computations, determines whether theyare equivalent.Their question is the following: among the collection of n cards, is there a set of more than n/2 of themthat are all equivalent to one another? Assume that the only feasible operations you can do with the cardsare to pick two of them and plug them…
5. Expand the information on the Transmission Control Protocol for this packet in the Wireshark “Details of selected packet” window (see Figure 3 in the lab writeup) so you can see the fields in the TCP segment carrying the HTTP message. What is the destination port number (the number following “Dest Port:” for the TCP segment containing the HTTP request) to which this HTTP request is being sent?