just to uncloak a bit. when we first decided to look at deprecating as-sets et alia, we begged olaf maennel to analyse the use thereof. the following is edited from internal email from early august. we then begged one of our number, warren, to do the dirty, and he was kind enough to do so. we owe him. --- using data from ripe r00 years total real stable as-sets as-sets 7 4 2 6 6 2 5 20 3 4 22 5 3 64 16 2 214 87 1 875 289 years stable is how many years that as-set was announced for that prefix. total as-sets is the number of prefixes that had any as-set. real as-sets is the number of prefixes with as-sets which were not singleton asns and were not private asns. olaf scanned for ten years but none were stable for more than seven. in ten years, 1205 different prefixes with as-sets were seen. removing private asns and removing singletons left only 404 prefixes over the ten years. he did not check for covering prefixes, i.e. two prefixes with the same as-set where one was a sub-prefix of the other, longer, one. and i suspect the data are somewhat self-similar. i.e. the 289 that were stable for the last year may have shorter term components which were much higher. i.e. looking at data for a week or a day may give higher values. a graph which should be pretty self-explanitory may be found at http://archive.psg.com/fraction-and-absolute-number-of-ASsets-in-table-over-... it is interesting that, at no time, i.e. in no single rib dump, were there more than 23 prefixes with as-sets. while this is suspicious, it seems to be true. randy