Re: [Rpm] Changes to RPM calculation for MacOS Ventura?

[Christoph Paasch <cpaasch@apple.com>]

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Hello,

> On Nov 1, 2022, at 3:09 PM, Sebastian Moeller <moeller0@gmx.de> wrote:
> 
> Hi Christoph,
> 
> On 1 November 2022 22:52:21 CET, Christoph Paasch via Rpm <rpm@lists.bufferbloat.net <mailto:rpm@lists.bufferbloat.net>> wrote:
>> Hello Jonathan,
>> 
>>> On Oct 28, 2022, at 2:45 PM, jf--- via Rpm <rpm@lists.bufferbloat.net> wrote:
>>> 
>>> Hopefully, Christoph can provide some details on the changes from the prior networkQuality test, as we’re seeing some pretty large changes in results for the latest RPM tests.
>>> 
>>> Where before we’d see results in the >1,500 RPM (and multiple >2,000 RPM results) for a DOCSIS 3.1 line with QoS enabled (180 down/35 up), it now returns peak download RPM of ~600 and ~800 for upload.
>>> 
>>> latest results:
>>> 
>>> ==== SUMMARY ====
>>> Uplink capacity: 25.480 Mbps (Accuracy: High)
>>> Downlink capacity: 137.768 Mbps (Accuracy: High)
>>> Uplink Responsiveness: Medium (385 RPM) (Accuracy: High)
>>> Downlink Responsiveness: Medium (376 RPM) (Accuracy: High)
>>> Idle Latency: 43.875 milli-seconds (Accuracy: High)
>>> Interface: en8
>>> Uplink bytes transferred: 35.015 MB
>>> Downlink bytes transferred: 154.649 MB
>>> Uplink Flow count: 16
>>> Downlink Flow count: 12
>>> Start: 10/28/22, 5:12:30 PM
>>> End: 10/28/22, 5:12:54 PM
>>> OS Version: Version 13.0 (Build 22A380)
>>> 
>>> Latencies (as monitored via PingPlotter) stay absolutely steady during these tests,
>>> 
>>> So unless my ISP coincidentally started having major service issues, I’m scratching my head as to why.
>>> 
>>> For contrast, the Ookla result is as follows: https://www.speedtest.net/result/13865976456  with 15ms down, 18ms up loaded latencies.
>> 
>> In Ventura, we started adding the latency on the load-generating connections to the final RPM-calulcation as well. The formula being used is now exactly what is in the v01 IETF draft.
> 
> [SM] I have been wondering quietly before whether reporting both inter- and intra-load-bearing flow responsiveness would not be a cool option for verbose mode? Both IMHO are giving relevant information about a link's usability under working conditions.

Yes, that’s a good suggestion! We could expose this in the verbose mode.


Christoph

> 
> Regards
>        Sebastian
> 
> 
>> 
>> Very likely the bottleneck in your network does FQ, and so latency on separate connections is very low, while your load-generating connections are still bufferbloated.
>> 
>> 
>> Ookla measures latency only on separate connections, thus will also be heavily impacted by FQ.
>> 
>> 
>> Does that clarify it?
>> 
>> 
>> Cheers,
>> Christoph 
>> 
>> 
>>> 
>>> Further machine details: MacBook Pro 16” (2019) using a USB-C to Ethernet adapter.
>>> I run with full ECN enabled:
>>> sudo sysctl -w net.inet.tcp.disable_tcp_heuristics=1 
>>> 
>>> sudo sysctl -w net.inet.tcp.ecn_initiate_out=1
>>> 
>>> sudo sysctl -w net.inet.tcp.ecn_negotiate_in=1
>>> 
>>> and also with instant ack replies:
>>> 
>>> sysctl net.inet.tcp.delayed_ack
>>> net.inet.tcp.delayed_ack: 0
>>> 
>>> I did try with delayed_ack=1, and the results were about the same.
>>> 
>>> Thanks in advance,
>>> 
>>> Jonathan Foulkes
>>> 
>>> _______________________________________________
>>> Rpm mailing list
>>> Rpm@lists.bufferbloat.net
>>> https://lists.bufferbloat.net/listinfo/rpm
>> 
> 
> -- 
> Sent from my Android device with K-9 Mail. Please excuse my brevity.


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