Re: [nmrg] Autonomic Use Cases

[Brian E Carpenter <[e-mail]>]

Michael and everybody,

I apologise for being silent for a month on the list, but various
things intervened.

Shortly, I'll be posting a first draft of a use case. First though, here
are a few comments on what Michael proposed for use cases. I have trimmed
the text of the proposal:

> Problem Statement: 

Yes, we certainly need this.

> Intended user / administrator experience: 

Yes

> Intent: Strictly speaking intent is part of the administrator experience, but should probably explained explicitly with a high-level view

Yes, but I'm not so sure it's part of the user experience. At least for
my use case, as you'll see, it's probably a vendor default.

> Local knowledge: What the function needs to know about the capabilities of the node itself, and which local resources need to be accessed.

I found this a bit abstract. Concretely, it's a matter of which parameters
each device can decide for itself, without external information. Logically,
therefore, it comes before intent (as far as the device is concerned).

> Communication requirements: The requirements for message exchange, discovery, negotiation, etc with other autonomic nodes.

Firstly, the communication might be with non-autonomic nodes too! Secondly,
I found this a bit closer to the solution than the problem. So in my
version, this topic is about the information needed from neighbor devices,
not about messages.

Also, I found that I needed to say something about monitoring
(which affects each device, so can't just be described as part of
the user experience, although it affects that too).

Finally, it seems useful to compare the AN use case with current
solutions. If we can't describe benefits, we are a bit stuck.

> Use cases are not required to outline a solution in detail

Understood. But it's a matter of taste and judgment where
the problem statement stops and hints of the solution begin...

Anyway - the best test for all this is an example use case, which
will come very soon.

   Brian




On 08/03/2014 12:47, Michael Behringer (mbehring) wrote:
> NMRG, 
> 
> During the meeting we mentioned the need to document use cases. This section in the definitions draft is so far empty. Since we should have that section BEFORE working out the use cases, I drafted something up here. 
> 
> I also realised that while we haven't really written down in the draft that the key point of this work really is to work out common infrastructure requirements. So I'm also suggesting an additional short section in the Design Goals section: 
> 
>       <section title="Common Autonomic Networking Infrastructure">
> 	<t><xref target="I-D.irtf-nmrg-an-gap-analysis"/> points out that there are already a number of fully or partially autonomic functions available today. However, they are largely independent, and each has its own methods and protocols to communicate, discover, define and distribute policy, etc. </t>
> 	<t>The goal of the work on autonomic networking in the IETF is therefore not just to create autonomic functions, but to define a common infrastructure that autonomic functions can use. This autonomic networking infrastructure may contain common control and management functions such as messaging, service discovery, negotiation, intent distribution, etc. A common approach to define and manage intent is also required. </t>
> 	<t>Refer to the reference model below: All the components around the "autonomic service agents" should be common components, such that the autonomic service agents do not have to replicate common tasks individually. </t>
>       </section>
> 
> Comments? Does this capture the idea well? 
> 
> And then, the use case section could look like this: 
> 
>       <section title="Guidelines for Case Studies">
> 	<t>Case studies and problem statements are mandatory to understand common requirements for autonomic functions. This section explains how case studies should be outlined and what they should describe:
>         <list style="symbols">
> 	  <t>Title</t>
> 	  <t>Problem Statement: An explanation which problem is being addressed, with information about existing solutions and their shortcomings.</t>
> 	  <t>Intended user / administrator experience: The goal of autonomic networking is to simplify network administration and usage. Use cases should point out how their experience differs from current solutions. If a use case depends on configuration, it may include configuration samples, although obviously the goal is to reduce or eliminate configuration. </t>
> 	  <t>Intent: Strictly speaking intent is part of the administrator experience, but should probably explained explicitly with a high-level view on how the autonomic function could be defined in intent (if required). </t>
> 	  <t>Local knowledge: What the function needs to know about the capabilities of the node itself, and which local resources need to be accessed.</t>
> 	  <t>Communication requirements: The requirements for message exchange, discovery, negotiation, etc with other autonomic nodes. </t>
>         </list>
> 	</t>
> 	<t>Use cases are not required to outline a solution in detail, nor to specify precise protocol or intent details. They are used at this point to determine a consolidated approach to developping an autonomic networking infrastructure. </t>
>       </section>
> 
> Comments? 
> Michael
> 
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