Re: [netmod] Clarification Question on draft-dsdt-nmda-guidelines-01

[Robert Wilton <[e-mail]>]

On 14/06/2017 16:23, Mahesh Jethanandani wrote:
>> On Jun 14, 2017, at 8:10 AM, Robert Wilton <[e-mail]> wrote:
>>
>> Hi Xufeng,
>>
>>
>> On 14/06/2017 14:01, Xufeng Liu wrote:
>>> Hi Juergen,
>>>
>>> Thanks for the confirmation.
>>> As for the distinction between applied configuration and operational, I think that it has been determined to be useful in some use cases. We can create a separate leaf in such a case.
>> Yes, I think that this is exactly the right approach.
>>
>> In the general case, a single leaf for applied configuration and the operational value is normally sufficient.
>>
>> But in some cases (e.g. where a value could be configured and/or negotiated via protocol) then it sometimes useful to both see the input into the protocol negotiation and also the resultant output value.
>>
>> Here, there is a choice to be made to decide whether the extra config false leaf represents the input value into the negotiation, or the output value.  I think that the decision probably depends on the protocol semantics, but all things being equal, there is a benefit if the configured value and actual operational value end up being represented by the same leaf/path (since this in the case in the mainline case where extra config false leaves are not required).
> Another way to look at it is whether the input value is truly different from the output value. For example, if the input value is auto-negotiation, a boolean, but the output value is a speed of 10/100/1000/10000, a uint32, then a separate leaf makes sense.
Yes, agreed.

For cases like these (e.g. Ethernet auto-negotiation) a good approach 
seem to be to model the leaf "enabling auto" as a separate leaf from the 
explicitly configured/operational value.

Thanks,
Rob


>
>> Thanks,
>> Rob
>>
>>
>>> Regards,
>>> - Xufeng
>>>
>>>> -----Original Message-----
>>>> From: Juergen Schoenwaelder [mailto:[e-mail]]
>>>> Sent: Tuesday, June 13, 2017 4:10 PM
>>>> To: Xufeng Liu <[e-mail]>
>>>> Cc: [e-mail]; [e-mail]
>>>> Subject: Re: Clarification Question on draft-dsdt-nmda-guidelines-01
>>>>
>>>> Hi,
>>>>
>>>> the typical -state tree consists of config false nodes and hence it represents
>>>> operational state. This is not a transitioning period question, this is how -state
>>>> trees were designed. Note also that the applied configuration is part of the
>>>> operational state in NMDA - for config true objects, there is no difference
>>>> between the applied configuration value and the operationally used value - they
>>>> are the same.
>>>>
>>>> /js
>>>>
>>>> On Tue, Jun 13, 2017 at 07:53:32PM +0000, Xufeng Liu wrote:
>>>>> During discussing the adoption of this guidelines, a question came up w.r.t. the
>>>> semantics of the non-NMDA "-state" module during the transitioning period:
>>>>> What kind of state do the leaves in the "-state" module represent? The applied
>>>> configuration or the actually used operational data?
>>>>> Since only of the two types can be represented, what is the guideline to model
>>>> the other type?
>>>>> Thanks,
>>>>> - Xufeng
>>>> --
>>>> Juergen Schoenwaelder           Jacobs University Bremen gGmbH
>>>> Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
>>>> Fax:   [phone]         <http://www.jacobs-university.de/>
>>> .
>>>
>> _______________________________________________
>> netmod mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/netmod
> Mahesh Jethanandani
> [e-mail]
>
>
>
> .
>