General comments: the doc is pretty straightforward in many of its aims but 
parts of it are confusing.  Certain sections need some copyediting and an 
infusion of 'the'.  It also barely touches on the idea of config models vs 
state data and ops, and this distinction is (I think) pretty lost at some 
points.  Do Standard models include config, state and ops?  Or are Standard 
models just some subset?  Do they *have* to be a subset?  Adding more 
discussion around the interplay of [standard, standard extension, proprietary, 
vendor] * [config, state, ops] would be interesting.

Specific comments:

1)
---
o  Based on the level of abstraction in the model

   o  Based on the applicability of the model

   The two categories are covered in the next two sections.

2.  First Dimension: YANG Data Model Layering
.....
3.  Second Dimension: Model Type
-----

The section titles should match the bulleted list.  Maybe the first dimension 
should be 'Model Abstraction Levels' and the second should be 'Model 
Applicability'?


2) 
Figure 1 lists both 'BGP' and 'Routing'.  I'm guessing from context that 
'Routing' really means 'RIB' or something, and I know there's been a lot of 
discussion I've been very vigorously disregarding, but maybe 'Routing' in this 
doc should read 'RIB' so as to not let the reader think it's shorthand for 
'Routing Protocol'?  Or if you intend for 'Routing' to mean 'Routing Protocol', 
then shouldn't BGP be subordinate to it?


3) 
--

   As an example, the Network Service model included in
   http://datatracker.ietf.org/doc/draft-l3vpn-service-yang/ provides an
---

Fix the reference to [I-D-l3vpn-service-yang] or whatever the right format is.



4) 
Section 3 gets a little tricky.  It seems to imply that the service models are 
built after the vendor models are built, and that the service models can only 
be built out of the pieces provided by vendor models.  While this makes sense 
on its face (you can't use a component to build a service if that component 
doesn't exist), it reads like SDOs are beholden to the vendors exposing the 
right bits before the SDOs can do anything.  Surely there's going to be some 
give and take here, where SDOs (or customers! ahem..) isssue standard service 
models and the vendors need to come up with config models to support them?  
It's also not clear exactly what turf 'vendor config models' is grabbing.  If 
we have a standard ACL model, for example, do I also need a vendor ACL config 
model?


5)
I'm not sure what value the discussion around routing protocol config (p. 8+) 
provides.  Does this schism of protocol vs vrf centricity apply to state and 
ops too?  Is it specific to config?  It's called out here but there's no 
conclusion, it just says "here's a thing".  Why is this thing more important 
than all the other things that could be mentioned?  Also, you may want to 
remove CLI from the discussion of centricity; it's clear that this is an 
IOS-vs-JunOS section.  If you're going to show both models, use YANG or 
pseudo-YANG to describe both.


6)
I don't get section 3.5.  Why is it there?  Just as a placeholder to say "this 
might happen"?  Shouldn't any discussion of vendor models either
        a) stay away from telling vendors what to do, or
        b) encourage vendors to get off of proprietary models ASAP once there's 
a standard one? 
That's sort of what "while waiting..." means, but I think this section either 
should be much bigger or not be there.


7)
I don't like the last paragraph of section 5.  What is it saying?  That the 
IETF can take the Linux kernel and write a standard model for it? 
I guess maybe it's trying to say "IETF must be the place where all models are 
blessed if they're about IETF technology"?
Is the RIB IETF technology?  What about an ACL?  
Does the IETF not recognize other sources of models for IP-and-SDN stuff?




eric

_______________________________________________
netmod mailing list
netmod@ietf.org
https://www.ietf.org/mailman/listinfo/netmod

Reply via email to