The first time I heard this idea was last year, from Noel Chiappa. Joel Halpern and I spent a while discussing it and decided it would scale surprisingly well. However, why would the major providers be motivated to implement it at all? Because it reduces routes... and it has other benefits, such as allowing subscribers to change providers within the provider group without renumbering. If you still have a copy of Yakov's ID on stratum based aggregation, you might check that out. Sorry, it's expired and I don't have a copy myself. Yakov and I are discussing overhauling the document and resubmitting it. Tony