Headscratcher of the week

Jonathan Lassoff jof at thejof.com
Fri May 31 22:39:39 UTC 2013


Those are some truly perplexing graphs. Quite strange that it appears
linear, as if something is slightly changing over time or
growing/shrinking at a constant-ish rate.

Do you have throughput or PPS graphs for the intermediate links as
well? Any similar correlations in the derivative slope?

My only hunch would be some intermediate buffer being increasingly
full over time, as some other application riding the path linearly
grows in packets/second or bits/second.

Cheers,
jof

On Fri, May 31, 2013 at 3:25 PM, Mike <mike-nanog at tiedyenetworks.com> wrote:
> Gang,
>
>         In the interest of sharing 'the weird stuff' which makes the job of
> being an operator ... uh, fun? is that the right word?..., I would like to
> present the following two smokeping latency/packetloss plots, which are by
> far the weirdest I have ever seen.
>
>         These plots are from our smokeping host out to a customer location.
> The customer is connected via DSL and they run PPPoE over it to connect with
> our access concentrator. There is about 5 physical insfastructure hops
> between the host and customer; The switch, the BRAS, the Switch again, and
> then directly to the DSLAM and then customer on the end.
>
>
> The 10 day plot:
> http://picpaste.com/10_Day_graph-YV3IdvRV.png
>
> The 30 hour plot:
> http://picpaste.com/30_hour_graph-DrwzfhYJ.png
>
>
>         How can you possibly have consistent increase in latency like that?
> I'd love to hear theories (or offers of beer, your choice!).
>
> Happy friday all!
>
>
> Mike-
>



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