What is Go-Back-N ARQ protocol?
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.
Where is Go-Back-N ARQ used?
Go-Back-N ARQ is mainly a specific instance of Automatic Repeat Request (ARQ) protocol where the sending process continues to send a number of frames as specified by the window size even without receiving an acknowledgement(ACK) packet from the receiver.
What is the efficiency of the Go-Back-N ARQ protocol?
Go-Back-N is easier to implement. In Selective Repeat, receiver window needs to sort the frames. Efficiency of Go-Back-N = N / (1 + 2a). Efficiency of Selective Repeat = N / (1 + 2a).
Why is it called Go-Back-N ARQ?
On the sender side for every packet send there is a time out timer which will expire for packet number 2. Now from the last transmitted packet 5 sender will go back to the packet number 2 in the current window and transmit all the packets till packet number 5. That’s why it is called Go Back N.
What is the full form of ARQ?
Automatic Repeat Request (ARQ) is an error-control mechanism for data transmission which uses acknowledgements (or negative acknowledgements) and timeouts to achieve reliable data transmission over an unreliable communication link.
What is the sender window size for Go-Back-N ARQ?
The size of the sending window determines the sequence number of the outbound frames. If the sequence number of the frames is an n-bit field, then the range of sequence numbers that can be assigned is 0 to 2n−1. Consequently, the size of the sending window is 2n−1.
What is window size in ARQ?
In Selective Repeat ARQ, the size of the sender and receiver window must be at most one-half of 2^m.
What is the size of sender window in Go-Back-N protocol?
The size of the sender’s window is 4. Step 1: As the window size is 4, so four packets are transferred at a time, i.e., packet no 1, packet no 2, packet no 3, and packet no 4.
What are the two types of ARQ?
Three main types of the ARQ are the Stop-and-wait ARQ, Go-Back-N ARQ, and Selective Repeat ARQ. Stop-and-wait ARQ is the simplest ARQ.
Which layer does ARQ exist?
layer 2 data link protocol
The ARQ is a layer 2 data link protocol (see OSI model). The sender waits for an acknowledgment (ACK) before sending the next frame. If the sender does not receive an ACK within a certain amount of time, or if it receives a not-acknowledged (NAK) message, the frame is retransmitted.
What is the size of sender window in Go-Back-N ARQ?
The size of the sender’s window is 4. Step 1: As the window size is 4, so four packets are transferred at a time, i.e., packet no 1, packet no 2, packet no 3, and packet no 4. Step 2: Once the transfer of window size is completed, the sender receives the acknowledgment of the first frame, i.e., packet no1.
What is the size of receiver window in Go-Back-N ARQ?
1
In Go-Back-N, N determines the sender’s window size, and the size of the receiver’s window is always 1. It does not consider the corrupted frames and simply discards them.