RFC 1889 specifies that the time interval between receiver RTCP reports include a randomization factor to avoid having all the receivers send at the same time. If all the receivers sent in the same 5% subinterval of their reply time interval, the arriving upstream RTCP traffic would rival the downstream RTP traffic

(a) Video receivers might reasonably wait to send their reports until the higherpriority task of processing and displaying one frame is completed; this might mean their RTCP transmissions were synchronized on frame boundaries. Is this likely to be a serious concern?

(b) With 10 receivers, what is the probability of their all sending in one particular 5% subinterval?

(c) With 10 receivers, what is the probability half will send in one particular 5% subinterval? Multiply this by 20 for an estimate of the probability half will all send in the same arbitrary 5% subinterval. Hint: How many ways can we choose 5 receivers out of 10?