Standards for last mile performance

The CRTC hearing went well (thanks for all your help).

One of the unanswered questions was how to set performance standards for
the last mile to ensure people get advertised speeds (within reason).

I had asked the question about contention ratio and it appears there is
no proper way to set such a moving target as a regulatory standard.

During the hearing, someone suggested that advertised speeds be
achievable 80% of the time. (chairman then asked if "time" was 24 hours,
or just the time you needed to use the internet (aka: peak).

Out of curiosity, could such a thing be measured by the last mile operator ?

There is the easy answer of synch. For DSL, non delivery of advertised
speed is easy since that metric is on the modem statistics. However, for
fixed wireless, would a customer too far from tower see a lower synch
rate or would he just see poor performance due to lots of retransmits ?

So some generic questions:

What are the different ways used to determine if the last mile is
congested and needs to be upgraded ?

From the network operator's point of view, would it not be looking at 5

minute throughput samples and trigger upgrades when it sees throughput
reaching x% of last mile segment capacity for more than X minutes per
day ?

What other means do network admins use to monitor when it is time to
upgrade shared last mile segments such as coax or fixed wireless ?

from a policy point of view, is it possible to set the same standard for
different technologies or should each (dsl, coax, fixed wireless and
satellite) have they own standards and methods of measurements before of
intrinsic differences in how they work ?

In the case of Rogers (canadian cableco), the CRTC record shows that
they trigger node split process when capacity reaches 60%. This is
because it takes them so long to do all the paperwork, committees etc
that by the time the node split is done, that segment has grown to about
75% utilisation.

Would that be a sound basis to set a policy ?

For shared last mile, would different technologies have similar
thresholds that trigger the need for upgrades or would coax start to
degrade at 75% whereas fixed wireless or satellite start to degrade at
lower/higher number ?

For FTTP, while likely not a big problem yet, would similar number apply
when the ~2gbps download and ~1gbps upload start to get filled by the 32
homes served ?

For us (FTTH) we had/have enough aggressive foresight to do smaller
splits.. 1x16. Some are doing 1x2's or 1x4's at the corner somewhere into
1x16's or 1x8's, so at the point where you start to hit decent saturation
you can just shrink the upstream split and fuse onto a new upstream strand
/ optic. Once that gets overused, thankfully you can overlay NG-PON2.

As far as measuring, in our case just having your NMS of choice just
monitoring the OLT via SNMP.

For fixed wireless, monitoring and management are the easy part. The hard
stuff is detecting what amounts to "dark matter", or the things you're not
normally looking for. Channel utilization (completely variable from moment
to moment), over all AP capacity, CPU usage, retransmissions, keeping per
client modulation rates very high to limit tdma timeslot utilization, etc.

The fixed wireless side ends up requiring a LOT of experience, monitoring,
and guesswork.

If you're being this aggressive, and then having to re-invest in the
next PON standard, isn't the case for Active-E being made more and more?


No. Active has higher initial and ongoing plant costs (cabinet power,
cabinet wear and tear, more battery banks, chargers, etc). You also end up
using far, far less fiber strands.

In addition, the upgrade path uses the same strands simultaneously.

I tend to disagree, but this is one of those debates that could go on

Lord knows I've been having it since 2008.


Disagreeing is okay. It wouldn't make you any less wrong though :stuck_out_tongue:

It hugely depends on the physical layout of the homes/area for economics of
active-E vs GPON... The scale of the outside plant aerial fiber is very
different in certain scenarios. A green field modern housing development
with everything underground might be very different than a semi-rural chain
shaped topology of GPON along a road of houses on 1 acre plots. Or an urban
townhouse development. Or a 35 floor condo tower.