nanog mailing list archives

Re: Initial Route Server Stats for MAE-East


From: Curtis Villamizar <curtis () ans net>
Date: Mon, 23 Oct 1995 15:12:43 -0400


In message <199510230144.VAA22194 () carbon cary mci net>, "Brett D. Watson" write
s:

  My point for interjecting here is to ask:

 Has anyone come up with *any* way to measure network performance (packet 
loss, throughput, delay) other than ping and traceroute?

LQM on non-PPP links sure would be great.  A number of times I've
suggested we consider LQM on bcast, with a set of LQM parameters per
ARP entry.  This way one end sends a LQM packet that serves as a time
marker, counts packets, then includes the count in the next LQM time
marker.  The receiver needs only count packets between LQM packets and
compare the local count against the count sent by the other end.  This
is an enormously oversimplified summary of LQM, but it just to make
the point that LQM is Good Stuff.

In the absence of LQM we have the DS3 MIB (poor substitute) and ping
for the FDDI rings (difficult to get any accuracy even with routes
that can respond very quickly to pings).  There are a ton of counters
for packets lost on the router itself (for various values of "the
router") that are thought to be accurate for congestion loss.  For
FDDI, usually packets not transmitted on the ring indicate the ring
has been too busy, but this is used more a trouble warning.

Curtis

ps - as you suggest, maybe some linux or bsdi boxes are appropriate
where the routers are unable to reliably return pings.


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