Ping triangulation

Todd Graham Lewis lists at
Sun Jul 28 04:05:18 UTC 1996

On Sat, 27 Jul 1996, Roy wrote:

> They use the ping times to figure out which server would be closest.
> All the servers are not located in the same place.  The idea is that 
> european users may receive better service from a european server.

This brings to mind a question: are ping times a more appropriate vector
than hopcount or topological locality?  Ping times reflect a lot of
important (but ephemeral) aspects of performance which more direct
measurements do not.  E.g., the latency of trans-pond links nicely
reflects their cost in a matter not easily captured in simple topology
maps.  Ditto for congested links which might be closer to the viewer. 

Of course cacheing solves all of these problems (J <- hook next to bait), 
but in this imperfect of worlds, what reasons, if any, make ping time 
less attractive than other metrics?  I used to think them simple-minded 
and sloppy, but now I am not so sure.

Todd Graham Lewis             Linux!                 Core Engineering
Mindspring Enterprises  tlewis at   (800) 719 4664, x2804

More information about the NANOG mailing list