Subject: Re: BFD MIB extension for MPLS-TP

From: Jeffrey Haas <[email-masked]>
Date: Sun, 8 Jan 2012 18:51:23 -0500

[cc: mpls chairs]

Sam,

I believe this MIB is in scope for the BFD WG charter:

"1. Develop the MIB module for BFD and submit it to the IESG for publication
as a Proposed Standard. 

5. Assist in the standardization of the BFD protocol for MPLS-TP. The
preferred solution will be interoperable with the current BFD
specification."

However, there's also some argument to keep all of the MPLS-TP MIB work
together in the MPLS WG.

Most of the MPLS-TP work, including MIBs, is occurring in the MPLS WG.
Doing a cursory review of the two other drafts you presented in the same
session, there is no strong binding from the oam-id or te-mib to the BFD
MPLS-TP MIB, but the MPLS-TP BFD MIB has a strong dependency on the oam-id
MIB.  The MPLS-TP BFD MIB depends on a common index from the bfd session
table.  Given these dependencies, it seems to make some some sense to keep
the MPLS-TP MIB work bundled together in on group.

I was not at IETF 82. Per the MPLS WG minutes it sounds like there is
some debate as to which WG would cover this work.  I personally have no
strong preference as to which group is in the draft name since the BFD WG
will be providing review, per charter, regardless of which group it is in.

With that, I pass the WG adoption token back to the MPLS chairs.  We're
happy to take on the work if you don't want it.

-- Jeff

On Thu, Dec 15, 2011 at 08:17:24PM -0800, Sam Aldrin wrote:
> Hello BFD WG,
> 
> 
> We have submitted a new draft, BFD MIB extensions to support MPLS-TP, prior
> to IETF82 at Taipei.
> 
> The draft is located at
> http://datatracker.ietf.org/doc/draft-vkst-bfd-mpls-mib/
> 
> 
> We have presented the draft in MPLS WG to get feedback from that WG.
> 
> As there was no WG session at Taipei, we are seeking feedback from BFD WG
> over the mailing list.
> 
> 
> The MIB extension is fairly simple and adds few new objects to extend the
> exiting BFD MIB and support BFD sessions over TP tunnels. Please provide
> your feedback and comments, so that, we could take it forward and ask to
> make it a WG document.
> 
> 
> Appreciate your time.
> 
> 
> cheers
> 
> -sam

---

From: Jeffrey Haas <[email-masked]>
Date: Sun, 8 Jan 2012 19:42:56 -0500

[Mostly writing as an individual contributor.]

> your feedback and comments, so that, we could take it forward and ask to

My first comment is that the object names in this MIB seem to strongly
suggest that this is a general extension MIB for BFD rather than are adding
MPLS-TP specific objects to the BFD MIB.  E.g.:
bfdExtObjects
bfdSessExtTable
etc.

I would strongly suggest the object names be more specific in alluding to
MPLS-TP.

SessionMapTypeTC should similarly note that it is associated with both BFD
and MPLS-TP.  Also, if there's any chance that this TC will see re-use, it
should be placed in its own MIB at some point in the future.  IMO, it's fine
to leave it in this document for a few iterations for refining the MIB.

bfdSessExtTable contains read-create objects but is INDEXed on the BFD
session table rather than AUGMENTing it.  As such it needs its own RowStatus
and StorageType objects.

bfdSessExtMapType and bfdSessExtMapPointer should probably get useful DEFVAL
entries that install an inactive row if the MIB user inadvertantly do a
createAnd* operation.  This may suggest that a map type of "none" may be
required.

-- Jeff

---

From: Sam Aldrin <[email-masked]>
Date: Thu, 12 Jan 2012 11:38:21 -0800

Hi Jeff,

Thank you for your comments. Please see inline for my replies to your questions.
Agree to all of your suggestions and comments.

Cheers
Sam

Sent from my iPad

> I would strongly suggest the object names be more specific in alluding to
%sam - agree. We will be changing the object names appropriately. As we are extending to support MPLS in general, not just TP, we will change accordingly.
> to leave it in this document for a few iterations for refining the MIB.
%sam - nod.
> session table rather than AUGMENTing it.  As such it needs its own RowStatus
%sam - yes, we missed adding those objects. Will do so in our next version.
> createAnd* operation.  This may suggest that a map type of "none" may be
%sam - good catch. We will be make appropriate changes.

---

From: Sam Aldrin <[email-masked]>
Date: Mon, 23 Jan 2012 22:06:54 -0800

[apologies for the delayed reply]

Hi Ross, George and Loa,

As Jeff has eluded to in the email, the MIB work for TP could all be within MPLS WG, even though the extensions are being done to support other areas like BFD. 

The draft was intentionally published within BFD WG as the extension is being done, in order to support MPLS including TP extensions, for the existing BFD MIB. When I presented at Taipei, the question was asked by AD that the adoption should be taken up within BFD WG, as draft belongs to BFD WG.

If I have to ask for WG adoption within MPLS WG, I need to move the draft to MPLS. I do not have any personal preference on where it should belong, as long as it gets adopted and we could proceed to finish the work.

So, could you please give us the guidance on how to proceed further? We are ready with new version of the draft, which we would like to submit ASAP.

Thanks in advance
-sam