In our rdt protocols, why did we need to introduce sequence numbers? in our rdt protocols, why did we need to introduce timers? suppose that the round trip delay between sender and receiver is constant and known to the sender. would a timer still be necessary in protocol rdt 3.0, assuming that packets can be lost? explain.

The use of phrases, fragments, and punctuation can influence the mood of a passage; keeping this in mind, how would you describe the mood of the followingpassage? "fog on the essex marshes, fog on the kentish heights, fog creeping into the cabooses of collier-brigs; fog lying out on the yards, and hovering in the riggingof great ships; fog drooping on the gunwales of barges and small boats. fog in the eyes and throats of ancient greenwich pensioners, wheezing by thefiresides of their wards; fog in the stem and bowl of the afternoon pipe of the wrathful skipper; fog cruelly pinching the toes and fingers of his shivering little'prentice boy on deck." (5 points)