21 Feb
2001
21 Feb
'01
3:43 p.m.
In message <200102212028.MAA50344@redpaul.mfnx.net>, Paul A Vixie writes:
Oh god, I hope not. RTT has never been an accurate predictor of end-to-end performance. (Just ask anyone who bought into ping-based global server load balancing.) ASPATH length is almost as bad (as a predictor) as RTT.
well, it's the way icmp_echo is handeld in some vendor routers and sometime also the poor implementation of an IP stack on the echoing device which is a problem.
no, that is not the problem. oh i admit that ping time jitter is ~random. but even if it weren't, RTT doesn't drive performance, (bw*delay)-loss does.
And how does "delay" differ from RTT, except for the obvious constant factor? --Steve Bellovin, http://www.research.att.com/~smb