[Bloat] DOCSIS cable modems that support PIE?

Neal Cardwell ncardwell at google.com
Mon May 13 11:13:18 EDT 2019


Thanks for the details!

Given that DOCSIS 3.1 (released initially in 2013) has many revisions -
https://specification-search.cablelabs.com/CM-SP-MULPIv3.1?v=03 -  and
low-latency DOCSIS and L4S was added in 2019 (CM-SP-MULPIv3.1-I17-190121),
I had been under the impression that the PIE AQM for upstream traffic was
also added in some later revision. But I do see now that the PIE AQM for
upstream traffic was in Annex M of the initial 3.1 spec
(CM-SP-MULPIv3.1-I01-131029).

Does anyone happen to know if (and if so, how widely) the major cable ISPs
world-wide enable the upstream PIE AQM functionality?

neal


*From: *Sebastian Moeller <moeller0 at gmx.de>
*Date: *Mon, May 13, 2019 at 5:16 AM
*To: *bloat, Neal Cardwell

Hi Neal,
>
> As far as I can tell the PIE aqm is mandatory in all DOCSIS 3.1 CPEs, do
> Al you need is a modem certified for 3.1 and probably also an DOCSIS ISP
> supplying 3.1 services (I assume the AQM will only be engaged in a docsis
> 3.1 environment), as in DOCSIS the ISP basically has control over the CPE,
> so you would need their cooperation. Not every DOCSIS ISP will provision
> any customer modem, but I assume you have enough leverage to make this
> happen.
>
> Anyway according to the spec sheets:
> AVM Fritzbox 6591
> Netgear CM1000-1AZNAS
> Arris SB8200
> Motorola MB8600
> should give you what you want.
>
> Best Reards
> Sebastian
>
> P.S.: I would love to hear your results, as information about the effects
> of docsis pie in the wild is quite limited...
>
>
> On May 12, 2019 11:24:50 PM GMT+02:00, Neal Cardwell <ncardwell at google.com>
> wrote:
>>
>> Anyone have a pointer to a cable modem model that is available for
>> purchase and implements the DOCSIS 3.1 PIE mechanism?  (So far, my searches
>> for this have only found other people asking this question, rather than the
>> answer. Apologies if I missed something that should be easy to find.)
>>
>> I'm curious to have one for testing with BBR v2. I'm aware of the Linux
>> PIE implementation, but it would be nice to have the actual cable modem
>> version to play with as well.
>>
>> Thanks!
>> neal
>>
>>
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