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

Sebastian Moeller moeller0 at gmx.de
Fri Aug 1 14:04:59 EDT 2014

Hi MIchael,

On Aug 1, 2014, at 06:51 , Michael Richardson <mcr at sandelman.ca> 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?

> The incumbent telco has significant
> incentive to make the backhaul network as congested and bufferbloated as
> possible, and to mis-crimp cables so that the DSL resyncs at different speeds
> regularly…  

	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.

> 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) ;)

> 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…

Best Regards

> -- 
> Michael Richardson
> -on the road-

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