What is Go-Back-N ARQ in computer networks?
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.
Which features of Go-Back-N ARQ?
Go – Back – N ARQ uses the concept of protocol pipelining, i.e. sending multiple frames before receiving the acknowledgment for the first frame. The frames are sequentially numbered and a finite number of frames. The maximum number of frames that can be sent depends upon the size of the sending window.
What is Go-Back-N ARQ and Selective Repeat ARQ?
In Go-Back-N, if a sent frame is found suspected or damaged, then all the frames are retransmitted till the last packet. In Selective Repeat, only the suspected or damaged frames are retransmitted.
What is ARQ and its types?
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. It has one frame at a time sent with no additional frames sent until reception of the previous one is confirmed via an acknowledgement signal.
Why is it called Go-Back-N?
The receiver accepts packets only in sequence; it does not buffer packets received out of order. Consequently, if the transmitter sends N packets and if the first is lost, then it must resend all the N packets starting from the first one. Hence the name Go-Back-N.
What is the efficiency of the Go-Back-N ARQ protocol?
In Go-Back-N ARQ, N is the sender window size, which we can see in the above example was 5. Now, here N should be greater than 1 in order to implement pipelining. If N=1, then our system reduces to Stop & Wait protocol. Now the efficiency of Go-Back-N ARQ = N/(1+2a), where a = tp/tt.
What is sliding window ARQ?
The Sliding Window ARQ (Automatic Repeat reQuest) protocols are of two categories − Go – Back – N ARQ. Go – Back – N ARQ provides for sending multiple frames before receiving the acknowledgment for the first frame. It uses the concept of sliding window, and so is also called sliding window protocol.
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.