Menu
I'm not understanding what is the dilemma in this figure. I only understood that if the window size is smaller than the sequence number then it's going to lead to some problems. This picture is addressing one of these problems:
929
It is also known as Sliding Window Protocol and used for error detection and control in the data link layer. 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.
If the ACK is not received, it re-transmits the previous packet again. The sender sends N packets which are equal to the window size. Once the entire window is sent, the sender then waits for a cumulative ACK to send more packets. On the receiver end, it receives only in-order packets and discards out-of-order packets.
The selective repeat ARQ is one of the Sliding Window Protocol strategies that is used where reliable in-order delivery of the data packets is required. The selective repeat ARQ is used for noisy channels or links and it manages the flow and error control between the sender and the receiver.
When the receiver receives a pkt0 he doesn't know if this packet is:
or
Solution:
Maximum allowable window size = half the sequence number space.
115
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
