Hi Wes,
On Jul 25, 2014, at 22:48 , Wes Felter <w...@felter.org> wrote:
> The Netgear stock firmware measures bandwidth on every boot or link up (not
> sure which) and I would suggest doing the same for CeroWRT.
>
> Do you need to measure Internet bandwidth or last mile bandwidth?
I think you want the bandwidth of the usual bottleneck, on DSL that
typically is the actual DSL-link to the DSLAM (even though the DSLAM is
oversubscribed typically its upstream link is not congested…). I think with
DOCSIS it is the same. Realistically bandwidth measurement are going to be
sporadic, so this will only help with pretty constant bottlenecks anyway, no
use in trying to track, say the DSLAM congestion that transiently happens
during peak use time...
> For link bandwidth it seems like you can solve a lot of problems by measuring
> to the first hop router.
And that would be sweet, but with DT’s network the first hop does not
respond to ICMP probes, nor anything else under end user control, also the
bottleneck might actually be in the BRAS, which can be upstream of the DSLAM.
What would be great is if all CPE would return the current link rates per SNMP
or so… Or if DSLAMs and CMTSs would supply data sinks and sources for easy
testing of good-put.
> Does the packer pair technique work on TDMA link layers like DOCSIS?
Toke and Dave dug up a paper showing that packet pair is not an
reliable estimator for link bandwidth, So one could send independent packet of
differing size, but then one needs to synchronize the clocks somehow…
Best Regards
Sebastian
>
> --
> Wes Felter
>
>
> _______________________________________________
> Cerowrt-devel mailing list
> Cerowrt-devel@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cerowrt-devel
_______________________________________________
Cerowrt-devel mailing list
Cerowrt-devel@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/cerowrt-devel
