For all transmit packets (those that experienced some retries, those that were successfully transmitted with only 1 transmission, and those that attempted max times and gave-up), the average number of RE-transmission attempts. Said another (though identical) way: the sum of all tranmission attempts divided by the number of unique packets attempted to be sent. Since SNMP does not convey decimal values, the result above is multiplied by 100. If there were no RE-transmissions, this value would be 0. If every single packet required exactly two tranmissions, this value would be 100, (representing 1.00).