number of bits=15 bits
total number of ticks before the clock cycles =2^15=32768 ticks
clock ticks every 100 msec,so total time elapsed for the clock to cycle around =32768*100*10^-3 =3276.8 seconds
maximum packet lifetime=60 seconds
(a) for the worst case no packet will be generated,in this case sender would enter the forbidden zone at 3276.8-60=3216.8 seconds
(b) at 240 sequence numbers/min ,the actual sequence number is 4t ,where t is the time in seconds
the left edge of the forbidden region =1/.1*(t-3216.8)
so 4t =1/.1*(t-3216.8) =>t= 5361.3 seconds
