Speaking about the CISCO's, no one thought about the memory when realised BGP there; the worst failures in the CISCO history was caused by some _temporary_ prefix leaks which caused routers to eat memory _permanently_ (last case was in our network 1 week ago when we leaked extra 20,000 prefixes to our access routers; it was fixed in a 5 minutes, but more then half of them get stomachache and refuse to work even when this leak disappeared... I don't blame the software designers, they must found the compromise between the stability, time_to_implement, cost and memory, but I'd like to highlight that they really did not concerned about such _cheap_ thing as memory at all). (let me to put -:) here).
On behalf of {myself, Paul, Ravi, Enke}, I assure you that Cisco's BGP has _always_ been worried about conserving memory. Tony