How does a selective repeat protocol work?

How does a selective repeat protocol work?

In the selective repeat, the sender sends several frames specified by a window size even without the need to wait for individual acknowledgement from the receiver as in Go-Back-N ARQ. In selective repeat protocol, the retransmitted frame is received out of sequence.

How is selective repeat better than go back n?

Selective Repeat is far better than Go back N in terms of retransmissions required. Bandwidth requirement is high because even if a single packet is lost, entire window has to be retransmitted. Selective Repeat is better than Go back N in terms of bandwidth requirement.

What is the significance of selective repeat?

An alternative strategy, the selective repeat protocol, is to allow the receiver to accept and buffer the frames following a damaged or lost one. Selective Repeat attempts to retransmit only those packets that are actually lost (due to errors) : Receiver must be able to accept packets out of order.

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 are the differences between Go-Back-N protocol and selective repeat protocol?

The main difference between these two protocols is that after finding the suspect or damage in sent frames go-back-n protocol re-transmits all the frames whereas selective repeat protocol re-transmits only that frame which is damaged.

What is Go-Back-N and selective repeat?

How does back N selective repeat work?

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.

Why selective repeat sliding window protocol accepts the packet in ordered sequence?

Selective Repeat attempts to retransmit only those packets that are actually lost (due to errors) : Receiver must be able to accept packets out of order. Since receiver must release packets to higher layer in order, the receiver must be able to buffer some packets.

What is selectselective repeat protocol?

Selective Repeat is an implementation of a sliding window protocol. In this article, we will discuss practice problems based on selective repeat protocol. The maximum window size for data transmission using the selective repeat protocol with n bit frame sequence numbers is-

What is the minimum window size required for Selective Repeat protocol?

Note: The sender’s window must be equal to the receiver’s window and the window size should be less than or equal to half of the sequence number in the selective repeat protocol. This is to avoid the data packets being recognized incorrectly.

What is Selective Repeat ARQ (automatic repeat request)?

The selective repeat protocol manages error and flows control between the sender and receiver. In this section, we will discuss the need for selective repeat ARQ (Automatic Repeat Request) and how it overcomes the shortcomings of the go-back-n protocol.

How does selective repeat (SR) work?

Now, selective repeat (SR) uses independent acknowledgment. It means that each frame that is sent to the receiver will be acknowledged independently. For more reference on types of acknowledgments, click here. Let’s see how SR actually works. Fig 1. Selective Repeat. Suppose, there are five frames that are to be transmitted. The window size is two.