Re: [ippm] Proposed changes to default settings in the Capacity metric load adjustment algorithm

[Martin Duke <[e-mail]>]

yes, let's make the change and proceed.

Thanks

On Wed, Aug 25, 2021 at 3:22 PM <[e-mail]> wrote:

> Hi, Martin et al.,
>
> my apologies for the late response.
>
> I've reviewed the proposed changes in the default values. I agree that
> these changes make the out-of-box capacity measurement less sensitive to an
> occasional non-congestion-related loss of packets while preserving the
> algorithm's fast ramp-up behavior. Clearly, a win-win update. I support it.
>
>
> Regards,
>
> Greg Mirsky
>
>
> Sr. Standardization Expert
> 预研标准部/有线研究院/有线产品经营部 Standard Preresearch Dept./Wireline Product R&D
> Institute/Wireline Product Operation Division
>
>
>
> E: [e-mail]
> www.zte.com.cn
> Original Mail
> *Sender: *MartinDuke
> *To: *MORTON JR., AL;
> *CC: *[e-mail];IPPM Chairs;[e-mail];
> *Date: *2021/08/12 10:49
> *Subject: **Re: [ippm] Proposed changes to default settings in the
> Capacity metric load adjustment algorithm*
> _______________________________________________
> ippm mailing list
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>
> Hello IPPM,
>
> If you have any comments about this change, please send them to this list
> no later than 24 August.
>
> On Tue, Aug 3, 2021 at 3:01 PM MORTON JR., AL <[e-mail]> wrote:
>
>> IPPM,
>>
>> I want to point out that some recent results conducted by others
>> encouraged us to test some additional values for seq error threshold and a
>> wider value range of values for consecutive errored status (during feedback
>> intervals).  We discovered that we would like to revise the default values
>> to make the load adjustment a little less-sensitive to
>> non-congestion-related loss and protect the fast ramp-up from ending
>> prematurely. For example, a very short burst of lost packets spanning the
>> boundary between two feedback intervals is currently sufficient to end fast
>> ramp-up.
>>
>> The current table in 8.1 contains:
>> +--------------+-------------+--------------+-----------------------+
>> | Parameter    | Default     | Tested Range | Expected Safe Range   |
>> |              |             | or values    | (not entirely tested, |
>> |              |             |              | other values NOT      |
>> |              |             |              | RECOMMENDED)          |
>> +--------------+-------------+--------------+-----------------------+
>> ...
>> +--------------+-------------+--------------+-----------------------+
>> | sequence     | 0           | 0, 100       | same as tested        |
>> | error        |             |              |                       |
>> | threshold    |             |              |                       |
>> +--------------+-------------+--------------+-----------------------+
>> | consecutive  | 2           | 2            | Use values >1 to      |
>> | errored      |             |              | avoid misinterpreting |
>> | status       |             |              | transient loss        |
>> +--------------+-------------+--------------+-----------------------+
>>
>>
>> The revised table rows would look like this:
>>
>> +--------------+-------------+--------------+-----------------------+
>> | Parameter    | Default     | Tested Range | Expected Safe Range   |
>> |              |             | or values    | (not entirely tested, |
>> |              |             |              | other values NOT      |
>> |              |             |              | RECOMMENDED)          |
>> +--------------+-------------+--------------+-----------------------+
>> ...
>> +--------------+-------------+--------------+-----------------------+
>> | sequence     | 10          | 0,1,5,10,100 | same as tested        |
>> | error        |             |              |                       |
>> | threshold    |             |              |                       |
>> +--------------+-------------+--------------+-----------------------+
>> | consecutive  | 3           | 2,3,4,5      | Use values >1 to      |
>> | errored      |             |              | avoid misinterpreting |
>> | status       |             |              | transient loss        |
>> +--------------+-------------+--------------+-----------------------+
>>
>> Somehow, persistent non-congestion-related loss had mostly eluded our
>> previous tests. But our goal has been to provide default values that will
>> work in automated testing run by anyone in any implementation or
>> circumstances - not just ~expert users and those who run the udpst utility.
>>
>> So we'd like to change default values for:
>>
>>   seq error threshold         from 0 to 10
>>   consecutive errored status  from 2 to  3
>>
>> and update our tested range/values column as well.
>>
>> Al
>>
>>
>