PSINet/Cogent Latency

Tue Jul 23 04:13:28 UTC 2002

On Mon, Jul 22, 2002 at 08:38:58PM -0700, william at elan.net wrote:
> 
> Is there patch or special config example available that would allow me
> to use mrtg (or rather rrdtool) to measure more often and then graph it
> in a way that would show standard 5-min graph but also separate line
> showing those micro burst and actual peak usage?

It's usually not practical to sample data that often, at least over snmp. 
30 seconds is reasonable if your poller doesn't suck (aka not mrtg), but 
thats still a fair amount of averaging.

As an example, looking at an interface doing 135Mbps average on a pretty
steady curve through Juniper's "monitor interface" which gives 2 second 
samples, I see between 120Mbps and 150Mbps fluctuations almost constantly.

Personally I would like to see the data collection done on the router 
itself where it is simple to collect data very frequently, then pushed 
out. This is particularly important when you are doing things like billing 
95th percentile, where a loss of connectivity between the polling machine 
and the device is a loss of billing information.

Why Juniper won't spend 5 minutes to make a simple lib so a program could
sample interface counters, so someone could write this kind of system to
run on the RE, is beyond me. I blame generations of dumbed down network
engineers wielding perl as their only tool. :)

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
PGP Key ID: 0x138EA177  (67 29 D7 BC E8 18 3E DA  B2 46 B3 D8 14 36 FE B6)