The Network Time Protocol Service can be used to synchronise computer clock. Explain why, even with this service, no guaranteed bound is given for the difference between two cooks.

Answer :

Any client using the ntp service must communicate with it by means of messages passed over a communication channel. If a bound can be set on the time to transmit a message over a communication channel, then the difference between the client’s clock and the value supplied by the ntp service would also be bounded. With unbounded message transmission time, clock differences are necessarily unbounded.