Problem $5(10$ points$)$: The Go$-$Back$-$N $($GBN$)$ protocol operates between nodes A and $B.$ Node $A$ is

to send frames F$0,$ F$1,$ F$2,$ F$3,$ and F$4$ only to node B$.$ There are no data frames to be sent after F$4.$

The frame exchange is as shown.

a$)(6$ points$)$ Complete the frame exchange diagram

showing the remaining frame exchanges and the

relevant events at node A and$/$or node $B.$ Must specify

whether the received frame is saved or discarded. Use

the provided diagram. Assume no errors or missing

frame occur other than the one shown in the diagram.

b$)(4$ points$)$ Assuming number of bits for sequence

numbers $k=3,$ what are the likely window sizes $($W$)$

that may this data link has? Explain very briefly.

GRN Protocol