Re: Network for Sale

["Steven M. Bellovin" <smb () research att com>]

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