In FDM$,$ if there are $8$ input signals each requiring a bandwidth of $3$ MHz$,$ what is the

minimum bandwidth required for the combined signal? $2$

$2.$ Compute the $12-$bit internet checksum for the following data. $5$

E$3$D $3$F$8$ AD$2$ F$75$

$2.$ Let there be $4$ bits reserved in the header for the frame sequence number. If the sliding

window protocol is used for flow control, $3$

a$)$ How many different frame sequence numbers are there?

b$)$ What is the maximum window size?

c$)$ Can you use a window of size $20?$