Re: [Lsr] When to augment LSR base YANG modules...

[<[e-mail]>]

Hi,

On one hand, I'm a bit worried about having too many tiny modules (finding the right module name to get the right feature, managing prefixes...). The good thing I see is that we could mandate in each LSR draft the YANG management part so both are published at the same time. While YANG is easy to write, it could still scare pure IGP guys that are focused on protocol encodings -> this implies that people may need to rely on people with YANG skills to write the management section.

On the other hand, we have few (or even no) experience today on managing modules revisions, do we also foresee some level of complexity ? The issue I see if we update the main YANG base module is that the timing may be different from the protocol encoding spec. Also, are we ready to publish a revision for each tiny feature ?(why not but who takes the pen ? Speaking as editor of ISIS yang module, I'm not really ready to have the pen to modify it for the rest of my life ;)

I think the main requirement (speaking as an operator) is to get the YANG part (ops+cfg) standardized at the same time. 


Brgds,


-----Original Message-----
From: Lsr [mailto:[e-mail]] On Behalf Of Christian Hopps
Sent: Friday, March 29, 2019 09:17
To: [e-mail]
Cc: [e-mail]
Subject: [Lsr] When to augment LSR base YANG modules...


The base YANG modules for IS-IS and OSPF both include operational state to describe TLV data. During the discussion about OSPFv3's version of this data, I brought up the issue of when and how the base modules should be augmented to add new TLV types to the model, suggesting it be done inline and with the RFC that adds the new feature/functionality to the protocol.

I'll go farther here and say this should apply to all the YANG required for management of the new feature, and it should all be added inline with the feature (i.e., in the same draft). In other words new features/functionality should include the YANG augment required to manage said features/functionality.

This has been suggested/tried previously with SNMP with varying (low) levels of success. The difference here is 1) YANG additions (a new module perhaps just augmenting the base) is easy, whereas SNMP wasn't. Additionally, operators weren't using SNMP to fully manage functionality (e.g., not doing configuration) so a requirement for extra work was harder to justify. Operators *do* want to fully manage their networks/servers with YANG though.

The argument against this during the meeting was that it would create many small modules. I don't find this compelling (i.e., "so"? :)

Assume I'm an operator -- the actual consumer of this management stuff:

  - If I'm going to use this new feature X, I need to be able to manage it. So I need it YANG for it. Not only do I need any new TLV data in the operational state, but I need the configuration and any other operational state right along with it. Otherwise each vendor has to add new YANG to their vendor modules, or the feature is useless to me. I can't use something if I can't turn it on.

  - I don't care about having many smaller modules that augment the base module -- at all. Quite the opposite actually, when new functionality is accompanied by it's own module it provides me a simple way to see if that functionality is present as the module will be present in the YANG capabilities announced by the device.

I'd be interested in hearing reasons we (as a WG) shouldn't just expect a YANG module (even if it's small) to be included with drafts that add new functionality.

Thanks,
Chris.

_________________________________________________________________________________________________________________________

Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc
pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler
a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration,
Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci.

This message and its attachments may contain confidential or privileged information that may be protected by law;
they should not be distributed, used or copied without authorisation.
If you have received this email in error, please notify the sender and delete this message and its attachments.
As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified.
Thank you.