Re: [Anima] What is intent ?

Brian E Carpenter <> Tue, 25 July 2017 23:04 UTC

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To: Toerless Eckert <>,
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From: Brian E Carpenter <>
Organization: University of Auckland
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Date: Wed, 26 Jul 2017 11:04:42 +1200
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Subject: Re: [Anima] What is intent ?
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Distribution trimmed to Anima:

Whenever I've asked "Is X Intent?", I've usually been told "No" except for
cases where X is too abstract to interpret algorithmically.

But in practice, I believe that many ASAs will need instructions from
the NOC to modify their default behaviour. I don't care what we call
those instructions; for the prefix management use case we just called
them "parameters".

So maybe Anima should focus on parameter distribution more than on
Intent. I think that's the point of draft-liu-anima-grasp-distribution.
A fairly simple change to the wording of draft-du-anima-an-intent
would adapt it to generic parameter distribution.

Converting abstract Intent to concrete parameters can be completely
separate from this, and could well be a centralised operation.

Or we could spend another 6 months discussing how to know Intent
when we see it. But I would prefer that to happen in NMRG.


On 26/07/2017 08:34, Toerless Eckert wrote:
> I have an autonomic network, and i want for another customer another
> L3VPN service instance in it.  How would i tell the network that i want
> this ? Via intent or via something else ?
> If it is something else, what is it ? I do not see any other information flow from
> operator to network beside intent in RFC7575 or draft-ietf-anima-reference-model. 
> Maybe i am missing something.
> If it is intent, how would it look like ? Could it simply be a definition
> of an L3VPN service instance in the model defined in rfc8049 ? If not, why not ?
> IMHO: Intent in ANIMA includes service definitions such as what rfc8049 is,
> except that we would reserve the right to eliminate all parameters of rfc8049
> for which we figure out autonomic ways to determine them. Which alas seems to
> be quite difficult for most parameters. 
> Other folks in the IETF clearly think that a service definition is NOT intent,
> but intent can only be some yet unclear high level policy. If thats the
> prevailing opinion/wisdom in the IETF, then IMHO we need to be more explicit about the
> fact that Intent is not the only input into the network but that there is
> also other input. Such as services. And anything else that people do not want to
> call Intent.
> Lets assume service and other necessary data operator->network should not
> be called intent. But lets say the superset of intent + services + everything
> else is called eg: "information". I think that draft-du-anima-an-intent
> would equally apply to all information we would want to distribute into
> an autonomic network. 
> Cheers
>     Toerless
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