【71-75】let us now see how randomization is done when a collision occurs . after a （71）， timeisdividedinto discrete slots whose length is equal to the worst-case round-trip propagation timeonether.to accommodate the longest path allowed by ethernet， the slot time has been set to 512bittimes，or 51.2us. after the first collision， each station waits either 0 or 1 （72） times before trying again.iftwostations collide and each one picks the same random number， they will collide again. afterthesecondcollision， each one picks either 0，1，2 or 3 at random and waits that number of slot times.ifathirdcollision occurs （the probability of this happening is 0.25）， then the next time the numberofslotsto wait is chosen at （73） from the interval 0 to 23-1. in general， after i collisions， a random number between 0 and 2i -1 is chosen， and thatnumberofslots is skipped. however， after ten collisions have been reached， the randomization （74）isfrozenat a maximum of 1023 slots. after 16 collisions， the controller throws in the towel and reportsfailureback to the computer. further recoveries up to （75） layers.
