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Re: Proposal to do away with netconf attributes in data model pay loads



On Fri, Apr 02, 2004 at 07:20:46AM -0800, Andy Bierman wrote:
 
> Here are the problems with (a):
> 
>   - specifying a NETCONF-only subset of XPath is not an
>     option.  It's all-or-nothing for XML standards like this

I fail to see the logic here. I guess your real concern is that once
there is a subset of XPATH, devices will end up supporting full XPATH
at the end anyway. While you believe this would be really bad, I tend
to believe that this might be not so bad.

>   - image footprint, memory/CPU requirements, coding and
>     testing complexity are all negatively impacted by 
>     the XPath implementation requirement.  The smaller
>     the device, the more this matters

Again, why is comparing subtrees any cheaper than parsing simple
XPATH path expressions? I asked the question before and did not
get a convincing answer.

>   - instance naming impacts the complexity and form of the
>     Xpath expressions. What is the canonical representation?
>     These data modeling issues won't be decided until after
>     the protocol is finished. 

This is a general observation, not an argument against XPATH. In fact,
it is an argument in favor of XPATH since we keep the flexibility
without over constraining the data modeling solution at this point.

>   - The Xpath expressions are not going to be interoperable,
>     since there are no guidelines at all how to use it.
>     Any attempt to impose order will require some netconf-specific
>     elements or attributes be encoded in the data model
>     (like Juergen's 'uri' attribute).  But this is the exact
>     problem the Xpath approach is supposed to solve.

I used uri's for naming, which is at this point treated as a data 
modeling issue. Obviously, there can't be guidelines for using
XPATH before the data model stuff has been worked out. This is a
feature, not a bug.
 
> IMO, option (c) is the easiest to implement (for agent and
> manager), the most readable, and the most interoperable
> choice we have.

I obviously disagree on all points (noting that interoperability
without at least specifying how naming works is impossible).

/js

-- 
Juergen Schoenwaelder		    International University Bremen
<http://www.eecs.iu-bremen.de/>	    P.O. Box 750 561, 28725 Bremen, Germany

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