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Questions tagged [go-back-n]

Go-Back-N ARQ is a specific instance of the automatic repeat request (ARQ) protocol, in which the sending process continues to send a number of frames specified by a window size even without receiving an acknowledgement (ACK) packet from the receiver.

Definition:

Go-Back-N ARQ is a specific instance of the automatic repeat request (ARQ) protocol, in which the sending process continues to send a number of frames specified by a window size even without receiving an acknowledgement (ACK) packet from the receiver.

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Go-Back-N window size

Why in TCP's Go-Back-N Algorithm window size(N) has to be smaller than the sequence number space(S): S>N? I tried figuring it out myself but don't quiet get it
Valera
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Datagram Socket Starving other threads in my UDP program

As part of a course assignment, we have been tasked with adding an extra layer of reliability on top of the UDP layer java offers in order to send a large picture file. This is to be done using the Go-Back-N protocol:…
Craig Innes
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In relation to GBN protocol, how does a single timer tracks time of sent unacknowledged packets?

In the book on networking "Computer Networking: A Top Down Approach" by James Kurose following is stated: "...sender in ... uses only a single timer, which can be thought of as a timer for the oldest transmitted but not yet acknowledged packet. If…
AJ HUNTER
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How to add sliding window mechanism to these programs?

I'd like to implement a sliding window mechanism into the following code, looking for any advice on where to start. Currently the sender keeps sending and collecting its own packets, and I'm not really sure why that is, could someone help me fix…
coderboy99
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Segmentation fault (core dumped) when trying to send a packet that contains a character array

Trying to send a packet that contains up to 30 characters along with other identifying information. Here is the constructor. packet::packet(int t, int s, int l, char * d){ type = t; seqnum = s; length = l; data = d; } For my class we're required to…
Austin Heath
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what is an 'outstanding' frame?

What is meant by outstanding frame ? I read this term while studying GBN protocol . From wikipedia: frames since the first lost frame are outstanding, and will go back to sequence number
program-o-steve
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How does a Go Back N sender handle out of order acknowledgements?

Based on my understanding, in Go Back N, an acknowledgement with sequence number i indicates that all packets up to and including i-1 have been acknowledged. Hence, if a sender has window size w, and base b, so the window is [b, b+w-1], and receives…
Michael Lee
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How to send data in previous screen with help of goBack()?

How to send data in previous screen with help of goBack() ? I tried already. For ex: this.props.navigation.navigate('Login', {name: this.state.name})
Divy Patel
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Go-Back N protocol ACK

I am trying to understand the working of Go-Back N using this website:- http://www.ccs-labs.org/teaching/rn/animations/gbn_sr/ Here, suppose we are sending frames 1,2,3,4,5,6 (window size 4) and in the current window we have frames 1,2,3,4. Now…
Zephyr
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What happens if the receiver's ACKs get lost?

For modulo 4 arithmetic, the sequence number ranges from 0-3 and the window size is 3(0-2). Suppose 3 packets from 0-2 are sent and the sender is waiting for an ACK from reciever. Suppose all 3 ACKs sent by the reciever are lost. At this time, the…
Pranay Saraiwala
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Trying to access object in an array of objects but only one object is saved

I'm trying to implement the GoBackN ARQ for a class. I'm attempting to read a file, break it up into packets of 30 characters and then store the packets in an array of packets. All of these packets are objects of the class packet. Currently, this…
Austin Heath
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Go back N protocol

I'm trying to implement the Go back N protocol on two separate client and server applications. Say my sequence numbers must fit 3 bits, so 2^3 = 8 max numbers, and 2^3 - 1 = 7 window size. I initially send my whole window. The first two packets (0…
Sotirios Delimanolis
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trying to add Go Back” function in WebView inside Fragment, but its showing this error

This is my code ERROR - " Type mismatch: inferred type is Unit but Boolean was expected " webview2.setOnKeyListener(View.OnKeyListener { fun onKey( int: Int, event: KeyEvent): Boolean { if (event.action == KeyEvent.ACTION_DOWN){ …
Jyotiraditya
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Go-back-n, with an ACK loss and a packet loss

While refreshing some old theory, and solving couple of problems, one instance had me confused: "7 packages (0 to 6) with window size 3 are sent. Packet no. 2 ACK is lost the first time it is sent, and packet number 4 gets lost the first time it is…
Saurus
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What is the ACK number using Go-Back-N?

In my lecture notes, the example of go back n shows that when reciever recieved a packet number n, reciever will send a ACK number n to the sender. But when i search on the web, some of the website said that reciever will send the n+1 ACK to the…
miketsui3a
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