On Tue, Apr 22, 2014 at 5:36 PM, Susan Hares <[email protected]> wrote:

> Andy:
>
>
>
> Catching up.  A few questions:
>
>
>
> 1)      Why do you think that only the RIB matters in the long run (Short
> run = RIB + BGP)
>

Why do you think I said that?
I don't see anything special about I2RS at all.
Editing operational state would probably work the same for other data.



> 2)      Your modeling questions are important .. so let me ask a
> meta-question and then go a level deeper...
>
>
>
> Why does netmod never really publish an informational model?
>
>
>

NETMOD publishes YANG modules.
I suppose it is perceived an unnecessary.


Andy




> Here's a bunch of answers/question to you great modeling questino
>
>
>
>   - What are the data types needed?  Is this a static set of will it ever
> change?
>
> a)      Yes.  Right now no Data types in
>
> This static set is likely to continually expand if it is used for I2RS,
> and have vendor specific
>
>
>
>   - What are the high level data modeling constructs needed?
>
> [Sue] Yes.  But we will talk a lot about what is high-level data model
> constructs?
>
>           Do you consider next-hop as defined in the RIB a high-level?
>
>
>
>   - Are user defined types needed?
>
> [Sue" If you mean, will vendors or specific end users need it?  I do not
> see how we can go without it.
>
>
>
>   - Are re-usable data definitions needed?
>
>   - Does the data model need to be modular?  How does it grow over time?
>
>  -Can vendors add data definitions that extend the standard definition?
>
>   - How are new definitions added in a way that does not break existing
> clients?
>
>
>
>    [Sue]:  Answer yes to all.  Re-usable, modular, growing, vendor
> extensible, user-defined.
>
>    Do not plan to break if add new,
>
>
>
>   - How is mandatory to implement vs. optional to implement functionality
> handled?
>
>   - How is mandatory to use vs. optional to use functionality handled?
>
>     [Sue]: Need the profiling variables that Yang is using
>
>               [Note: Forces has an equivalent to all of this]
>

>
> Sue
>
>
>
>
>
> *From:* i2rs [mailto:[email protected]] *On Behalf Of *Andy Bierman
> *Sent:* Saturday, April 19, 2014 1:46 PM
> *To:* Russ White
> *Cc:* [email protected]; Edward Crabbe; Jamal Hadi Salim; Dean Bogdanovic;
> Jan Medved (jmedved); Joel M. Halpern
> *Subject:* Re: [i2rs] consensus on I2RS protocol and model
>
>
>
> Hi,
>
>
>
> On Sat, Apr 19, 2014 at 8:22 AM, Russ White <[email protected]> wrote:
>
>
> > And the basic premise of I2RS is that there are requirements for the work
> > that were not addressed properly by the existing configuration protocols.
> > Otherwise the WG would not even need to discuss protocol modifications.
> > So the fact that NetConf / YANG works for device configuration does not
> > seem to be evidence that it works for what I2RS wants to do.
>
> Precisely. Otherwise, we could have just looked at the problem, and said,
> "let's use YANG." But I think we're starting to confuse the problem set
> because we started by trying to boil the ocean. Once you actually get to
> town, it's hard to keep in focus that you're just there for a new pitchfork
> handle -- that game of checkers over there on the porch of the hotel looks
> so interesting, and the hardware store has so much other stuff than just
> pitchfork handles, after all.
>
> So, given we are _supposed_ to be focused on the RIB interface, and not
> protocol, configuration, device, etc., etc., what specific points have the
> use cases brought out that either NETCONF/YANG or FORCES not fulfill? One
> of
> the primary points was timing -- are these other systems fast enough?
>
> >From my perspective, these two systems don't fulfill the I2RS mandate on
> the
> RIB side for various reasons:
>
> - I'm not convinced on the speed side. YANG feels a bit heavy weigh for
> what
> we want here. The flexibility is there, but so is the cost of that
> flexibility.
>
>
>
>
>
> Can you explain how an off-line representation of the data model can be
> fast or slow?
>
> You mean the YANG compiler takes too long to process a YANG file?
>
> You mean the unspecified I2RS protocol will be too slow on the wire if
>
> it uses XML or JSON encoding of YANG data structures?
>
>
>
>
>
>
> - I'm not convinced YANG has handled the atomicity issues in a way that
> makes sense for the application environment we have in mind. RESTCONF seems
> to go that direction, but I'm not certain it's a complete solution (?).
>
>
>
> YANG is a data modeling language.
>
> RESTCONF is a protocol.
>
> Atomicity is a property of the protocol.
>
> Which YANG statements prevent this from being accomplished in the TBD I2RS
> protocol?
>
>
>
>
>
> So, IMHO, I think we need to either consider FORCES, or "something new."
> But
> we're going to have a hard time determining if this is true if we can't
> make
> a solid requirements list. For me, these are:
>
> - Atomic operations at the RIB level
> - Speed that's comparable to a local routing process installing routes in
> the RIB
> - An immediate feedback system within the RESTful mold that tells the
> installing process what happened, and why, with the route it just tried to
> install in the RIB
>
> So, it seems to me that we need to return to the use cases -- there are two
> in the charter. If we want to discuss adding others, that's fine, but we
> need to gain some focus, and stop trying to boil the ocean, if we want to
> make any progress.
>
>
>
> It seems to me this WG needs to start asking the right questions about the
>
> data modeling language requirements.  E.g.:
>
>
>
>   - What are the data types needed?  Is this a static set of will it ever
> change?
>
>   - What are the high level data modeling constructs needed?
>
>   - Are user defined types needed?
>
>   - Are re-usable data definitions needed?
>
>   - Does the data model need to be modular?  How does it grow over time?
>
>   - Can vendors add data definitions that extend the standard definitions?
>
>   - How are new definitions added in a way that does not break existing
> clients?
>
>   - How is mandatory to implement vs. optional to implement functionality
> handled?
>
>   - How is mandatory to use vs. optional to use functionality handled?
>
>
>
> You are asking about protocol requirements, not data modeling.
>
> IMO it would be near-sighted and extremely impractical to choose
>
> a language that only supported description on RIB info.  I fail to see what
>
> is so special about RIB info that would warrant its own DML.
>
>
>
>
>
> :-)
>
> Russ
>
>
>
> Andy
>
>
>
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