What is the difference between stop and wait ARQ and Go-Back-N ARQ?
Go-Back-N ARQ is a more efficient use of a connection than Stop-and-wait ARQ, since unlike waiting for an acknowledgement for each packet, the connection is still being utilized as packets are being sent. In other words, during the time that would otherwise be spent waiting, more packets are being sent.
What is ARQ explain stop and wait go back n and selective repeat ARQ?
In Stop and Wait protocol, no specific order is needed at receiver end. In GoBackN protocol, in-order delivery only are accepted at receiver end. In Selective Repeat protocol, out-of-order deliveries also can be accepted at receiver end.
What is meant by stop and wait ARQ?
Stop-and-wait ARQ, also referred to as alternating bit protocol, is a method in telecommunications to send information between two connected devices. It ensures that information is not lost due to dropped packets and that packets are received in the correct order.
For what kind of network stop and wait ARQ and Go-Back-N ARQ used?
Comparison Table-
| Stop and Wait ARQ | Go back N | |
|---|---|---|
| CPU usage | Low | Moderate |
| Level of difficulty in Implementation | Low | Moderate |
| Acknowledgements | Uses independent acknowledgement for each packet | Uses cumulative acknowledgements (but may use independent acknowledgements as well) |
| Type of Transmission | Half duplex | Full duplex |
Is go back ARQ bandwidth efficient?
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.
Why stop and wait ARQ protocol is called so?
Rule 2: Sender sends the next packet only when it receives the acknowledgment of the previous packet. Therefore, the idea of stop and wait protocol in the sender’s side is very simple, i.e., send one packet at a time, and do not send another packet before receiving the acknowledgment.
What is Go-Back-N and selective repeat?
Definition. 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 the full form of ARQ?
1 ARQ Principles. 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.
Which one is true in case of stop and wait ARQ?
In stop and wait ARQ, Sender window size is 1. This allows the sender to keep only one frame unacknowledged. So, sender sends one frame and then waits until the sent frame gets acknowledged.
What are the draw backs of stop and wait protocol?
Disadvantages of Stop and Wait protocol
- Problems occur due to lost data. Suppose the sender sends the data and the data is lost.
- Problems occur due to lost acknowledgment. Suppose the sender sends the data and it has also been received by the receiver.
- Problem due to the delayed data or acknowledgment.
What initiates go back N ARQ?
Go-Back-N ARQ uses a cumulative acknowledgment technique, which means receiver starts an acknowledgment timer whenever it receives a data packet which is fixed & when it expires, it will transmit a cumulative acknowledgment for the number of data packets received in that interval of time out timer.
What is pure aloha in networking?
There are two types of ALOHA protocols – Pure ALOHA and Slotted ALOHA. In pure ALOHA, the time of transmission is continuous. Whenever a station has an available frame, it sends the frame. If there is collision and the frame is destroyed, the sender waits for a random amount of time before retransmitting it.