Differences between Go Back N ARQ and Selective Repeat ARQ

The basic difference between Go Back N ARQ and Selective Repeat ARQ

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

Selective Repeat ARQ/Selective Reject ARQ is a specific instance of the automatic repeat-request protocol used to solve sequence number dilemmas in communications. 

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Go Back And ARQ

• Go Back N ARQ is inefficient for the noisy link.
• Go Back N ARQ is less complicated than Selective Repeat ARQ.
• Go Back N ARQ Sender Windows Size is 2^(m)-1 and receiver window size is 1.
• Go-Back-N ARQ is a specific instance of the automatic repeat request (ARQ) protocol, in which the sending process continues to send the number of frames specified by a window size even without receiving an acknowledgment (ACK) packet from the receiver. It is a special case of the general sliding window protocol with the transmit window size of N and receive window size of 1.

Selective Repeat ARQ

• Selective repeat ARQ is efficient for noisy links.
• Selective Repeat ARQ is Complicated.
• In Sender and Receiver Window Size is 2^(m-1).
• Selective Repeat ARQ / Selective Reject ARQ is a specific instance of the Automatic-Repeat-Request (ARQ) protocol used for communications. It may be used as a protocol for the delivery and acknowledgment of message units, or it may be used as a protocol for the delivery of subdivided message sub-units.

Wrapping it up

“Go-Back-N Protocol” and “Selective Repeat Protocol” are the sliding window protocols. The Sliding window protocol is primarily an error control protocol. It is a method of error detection and error correction.

The basic difference between the go-back-n protocol and selective repeat protocol is that the “go-back-n protocol” retransmits all the frames that lie after the frame which is damaged or lost.

The “selective repeat protocol” retransmits only that frame that is damaged or lost.