Re: [alto] IESG evaluation results

[Martin Duke <[e-mail]>]

Hi Richard,

Yes, I agree that metric collection is out of scope. However, to the extent
that we can import very precise definition (perhaps saying that ALTO
servers SHOULD post measurements as close to this definition as possible?)
it will save a lot of text and review.

On Fri, Dec 3, 2021 at 11:06 AM Y. Richard Yang <[e-mail]> wrote:

> Hi Martin,
>
> Add the WG, so that we can hear others' comments as well. Please see below
> for a small addition.
>
> On Fri, Dec 3, 2021 at 1:46 PM Y. Richard Yang <[e-mail]> wrote:
>
>> Martin,
>>
>> Thanks a lot for the update! A quick reply on performance metrics.
>>
>> On Fri, Dec 3, 2021 at 1:22 PM Martin Duke <[e-mail]>
>> wrote:
>>
>>>
>>> 2) We will have to do something about performance-metrics. In the
>>> telechat, we agreed that metrics collection is out of scope.
>>>
>>
>> Not sure I understand what metrics collection refers to. Could you please
>> add a bit of detail?
>>
>>
>>> However, more precise definitions of these metrics are in scope. I would
>>> suggest finding RFCs in the ippm WG stream that contain useful definitions
>>> and using those.
>>>
>>
>> Going down the path ippm can lead to potential issues. The
>> current metrics definitions are more based on deriving path metrics from
>> link metrics reported in the routing system (e.g., BGP-LS). This is how
>> current deployment (e.g., Flow Director, Lui's team) works and hence is
>> proven to be feasible. I do not see that the routing systems will start to
>> ask routing devices to measure link properties using ippm measurements, and
>> then report using routing protocols. Then conforming to ippm measurement
>> metrics can lead to higher deployment barriers. We sure can take a look but
>> want to point out the potential problem first.
>>
>>
> Almost all metrics are derived from BGL-LS metrics (RFC8571). Hence, it is
> not clear what more precise definitions mean. Does it mean that those
> definitions in RFC8571 (which are defined in IGP existing IGP protocols)
> are not precise, and hence should not be used (and hence switch to ippm
> type of metrics, which specify many more parameters such as traffic
> patterns)? Or it means that the performance metric document should just
> make a single reference, and the IGP metrics as already defined by IETF are
> acceptably "precise".
>
> Or maybe it is only about the tput metric, and if so, we can discuss it
> carefully.
>
> Thanks a lot,
> Richard
>
>
>
>
>
>
>> Thanks.
>>
>> Richard
>>
>