[Cerowrt-devel] Ideas on how to simplify and popularize bufferbloat control for consideration.

Michael Richardson mcr at sandelman.ca
Sat Aug 2 16:17:32 EDT 2014

Sebastian Moeller <moeller0 at gmx.de> wrote:
    >> Sebastian Moeller <moeller0 at gmx.de> wrote:
    >>> No idea? How would you test this (any command line to try). The good
    >>> thingg with the ping is that often even the DSLAM responds keeping
    >>> external sources (i.e. hops further away in the network) of
    >>> variability out of the measurement...
    >> With various third-party-internet-access ("TPIA" in Canada), the DSLAM
    >> is operated by the incumbent (monopoly) telco, and the layer-3 first
    >> hop is connected via PPPoE-VLAN or PPP/L2TP.

    > 	So they “own” the copper lines connecting each customer to the DSLAM?
    > And everybody else just rents their DSL service and resells them? Do
    > they really connect to the DSLAM or to the BRAS?

correct, the copper continues to be regulated; the incumbent was given a
guaranteed 11-14% profit on that service for the past 75 years...

Third parties get an NNI to the incumbent in a data centre.
1) for bridged ethernet DSL service ("HSA" in Bell Canada land), the
   each customer shows up to the ISP in a VLAN tag.
2) for PPPoE DSL service, the traffic comes in a specific VLAN, over
   IP (RFC1918) via L2TP.

Other parties can put copper in the ground, and in some parts of Canada, this
has occured.  Also worth mentioning that
AlbertaGovernmentTelephone/EdmontonTel/BCTel became "TELUS", and then left
the Stentor/Bell-Canada alliance, so Bell can be the third party in the west,
while Telus is the third party in the centre, and Island/Aliant/NBTel/Sasktel
remain government owned... and they actually do different things as a result.

    > 	I think in Germany the incumbent has to either rent out the copper
    > lines to competitors (who can put their own lines cards in DSLAMs
    > backed by their own back-bone) or rent “bit-stream” access that is the
    > incumbent handles the DSL part on both ends and passes the traffic
    > either in the next central office or at specific transit points. I
    > always assumed competitors renting these services would get much better
    > guarantees than end-customers, but it seems in Canada the incumbent has
    > more found ways to evade efficient regulation.

This option exists, but the number of CLECs is large, and the move towards
VDSL2 / Fiber-To-The-Neighbourhood (with much shorter copper options!!) means
that this is impractical.

    >> my incumbent telco's commercial LAN extension salesperson proudly told
    >> me how they never drop packets, even when their links are congested!!!

    > 	I really hope this is the opinion of a sales person and not the
    > network operators who really operate the gear in the “field”. On the
    > other hand having sufficient buffering in the DSLAM to never having to
    > drop a packet sounds quite manly (and a terrible waste of otherwise
    > fine DRAM chips) ;)

I think much of the buffer is the legacy Nortel Passport 15K that ties much
of the system together...

    >> The Third Party ISP has a large incentive to deploy equipment that
    >> supports whatever "bandwidth measurement" service we might cook up.

    > 	As much as I would like to think otherwise, the only way to get a BMS
    > in the field is if all national regulators require it by law (well
    > maybe if ITU would bake it into the next xDSL standard that the DSLAM
    > has to report current line speeds as per SNMP? back to all down stream
    > devices asking for it). But I am not holding my breath…

My position is that if there isn't a technical specification, no regulation
could possibly follow...

]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     mcr at sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [

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