Subject: [nsc] Manageability tasks for SFC

From: Thomas Narten <[email-masked]>
Date: Fri, 01 Nov 2013 10:45:53 -0400

Looking at the proposed charter
(https://datatracker.ietf.org/doc/charter-ietf-sfc/), it includes:

> Specifically, the SFC WG is chartered to deliver the following:
...
> 
> 5) Manageability: This document will address the management of service
>     function chaining including relevant MIBs and YANG information and
>     data modules, and service function chaining diagnostics. 

And in the milestones, says:

> Request the IESG for publication of an Informational document defining
> SFC manageability including diagnostics, and MIB and YANG
> information/data models to IESG

My take is that this group will need to do some work in this
space. But it is not at all clear to be yet *what* that work will
be. IMO, having the charter say we will do MIBs and YANG info models
may be getting ahead of ourselves.

As an initial step, I think we need to look at requirements. I don't
know if we really understand just what we want to "manage". For
example, any information model dealing with services presumably will
depend on deciding to what degree service are "discovered" dynamically
vs. just having their existance configured as part of an overall
orchestration system.

My suggestion would be to tweak the mileston wording to make clear we
will first do some work to scope what we need to do in this space, and
then figure out the specific deliverables. Personally, I'm OK with
just having the charter say we will do requirements and then recharter
when we have a better idea of exactly what we need to do. What I don't
think we should do yet is commit to doing (say) a YANG module. We may
decide we want to do so later, but I think its premature to say so
now.

Thoughts?

Thomas

---

From: Melinda Shore <[email-masked]>
Date: Fri, 1 Nov 2013 07:22:48 -0800

I think that level of specificity is pretty clearly getting ahead of things
(like, oh, say, requirements).  FWIW nsc/nfv operational issues, including
management,  will be discussed during the opsawg session on Tuesday.
We're already seeing some draft submissions.

Melinda

---

From: Thomas Narten <[email-masked]>
Date: Fri, 01 Nov 2013 11:51:33 -0400

So, Jim and I chatted some more about this issue, and our current
thinking is that the first step here is a combination of requirements
and framework. And that it's even unclear whether to call this
"managment" or "control plane".

For framework, we need to understand what types of operations need to
be done in this space. For example, information needs to get pushed
out to the Service Functions that allow them to properly understand
and process the data packets (and the service header fields/metadata
associated with those data packets).

But there are (at least) two rather different ways to do this. One
could view it as management problem, where information needs to be
pushed out to the individual service points via something like
netconf. I.e., one is "managing" the service functions and
"configuring" them. This could be done as (say) part of a more general
orchestration system.

Or, the info could be distributed via routing protocols.

Those two approaches are very different in terms of protocol/solution
implications.

Hence, a framework discussion would help sort out how to approach this
space.

Thomas

---

From: "Joel M. Halpern" <[email-masked]>
Date: Sat, 02 Nov 2013 20:48:53 -0400

I tend to prefer to recognize a strong distinction between application 
processing and forwarding logic.  This leads me to treat information 
needed by service instances to service packets as a very different kind 
of thing than routing / forwarding information.

Whether that kind of information is injected into the applications via 
management or "sdn" (for any particular value of "sdn" you choose) 
doesn't really matter to me.

Yours,
Joel

On 11/1/13 11:51 AM, Thomas Narten wrote:
> _______________________________________________
> nsc mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/nsc
>

---

From: "Romascanu, Dan (Dan)" <[email-masked]>
Date: Sun, 3 Nov 2013 15:14:58 +0000

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf Of
> Thomas Narten
> Sent: Friday, November 01, 2013 4:46 PM
> To: [email-masked]
> Subject: [nsc] Manageability tasks for SFC
> 
> My take is that this group will need to do some work in this space. But
> it is not at all clear to be yet *what* that work will be. IMO, having
> the charter say we will do MIBs and YANG info models may be getting
> ahead of ourselves.
> 
> know if we really understand just what we want to "manage". For example,
> any information model dealing with services presumably will depend on
> deciding to what degree service are "discovered" dynamically vs. just
> having their existance configured as part of an overall orchestration
> system.
> 
> then figure out the specific deliverables. Personally, I'm OK with just
> having the charter say we will do requirements and then recharter when
> we have a better idea of exactly what we need to do. What I don't think
> we should do yet is commit to doing (say) a YANG module. We may decide
> we want to do so later, but I think its premature to say so now.
> 
> Thoughts?
> 
> Thomas
> 

[[DR]] I fully agree with Thomas here. 

Regards,

Dan

---

From: Thomas Narten <[email-masked]>
Date: Wed, 06 Nov 2013 10:38:16 -0800

There have been some additional offline discussions on this topic, and
we propose to change the charter in the following ways:

New text for item 5) in the charter:

    5) Manageability: Work on the management and configuration of
       service functions in support of SFC components will certainly
       be needed, but first needs to be better understood and scoped.

Replace previous milestone on management with:

    May 2014 Consult with OPS Area on possible charter modifications
	     for management and configuration of SFC components

Thomas

---

From: Tina TSOU <[email-masked]>
Date: Wed, 6 Nov 2013 18:41:06 +0000

Dear Thomas,
Fully agreed. Thank you for taking consideration of it.

Thank you,
Tina

> Sent: 2013年11月6日 10:38
> Subject: Re: [nsc] Manageability tasks for SFC
>

---

From: "Joel M. Halpern" <[email-masked]>
Date: Wed, 06 Nov 2013 16:44:25 -0500

I find the proposed wording of bullet 5 a little odd.
Service functions are applications.  I would hope that application 
management is out of scope for this working group.  (I can't tell if I 
have a problem with the actual milestone, as that depends upon exactly 
what the scope of a service function chain component is.  Management of 
the chaining seems worth discussing.

Yours,
Joel

---

From: Melinda Shore <[email-masked]>
Date: Wed, 06 Nov 2013 13:49:55 -0800

> the chaining seems worth discussing.

Right, I think it's worth thinking about visibility into and
management of each of the service functions, independent of
the application they're supporting.  Things like status monitoring
and reporting, instantiation, etc.

Melinda

---

From: "Diego R. Lopez" <[email-masked]>
Date: Wed, 06 Nov 2013 22:08:42 +0000

I agree. Probably using the wording suggested by Melinda ("management of each of the service functions, independent of the application they're supporting") would make things clear in that respect...

Be goode,

--
"Esta vez no fallaremos, Doctor Infierno"

Dr Diego R. Lopez
Telefonica I+D
http://people.tid.es/diego.lopez/

e-mail: [email-masked]
Tel:    +34 913 129 041
Mobile: +34 682 051 091
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From: "Joel M. Halpern" <[email-masked]>
Date: Wed, 06 Nov 2013 17:26:28 -0500

That still looks like application management.  In fact, it looks like 
the exact same application management you want when you are not doing 
service chaining.  Which is why I have trouble seeing how it fits in 
this working group.

Yours,
Joel

---

From: Melinda Shore <[email-masked]>
Date: Wed, 06 Nov 2013 14:27:41 -0800

> service chaining.  Which is why I have trouble seeing how it fits in

It may not fit in *this* working group but you'd still need
interfaces on the services to effect management functions.

Melinda

---

From: Andre Beliveau <[email-masked]>
Date: Wed, 6 Nov 2013 22:31:24 +0000

How about this formulation:

"Work on the management and configuration of SFC components related
to the support of Service Functions Chaining will certainly be needed,
but first needs to be better understood and scoped."

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Joel M. Halpern
Sent: November-06-13 2:26 PM
To: Melinda Shore; [email-masked]
Subject: Re: [nsc] Manageability tasks for SFC

That still looks like application management.  In fact, it looks like the exact same application management you want when you are not doing service chaining.  Which is why I have trouble seeing how it fits in this working group.

Yours,
Joel

On 11/6/13 4:49 PM, Melinda Shore wrote:
>> management is out of scope for this working group.  (I can't tell if 
>> I have a problem with the actual milestone, as that depends upon 
>> exactly what the scope of a service function chain component is.  
>> Management of the chaining seems worth discussing.
>
> management of each of the service functions, independent of the 
> application they're supporting.  Things like status monitoring and 
> reporting, instantiation, etc.
>
> Melinda
>
>

---

From: "Joel M. Halpern" <[email-masked]>
Date: Wed, 06 Nov 2013 17:33:37 -0500

We don't generally include in a WG charter work that we hope some other 
working group will choose to do.

Yours,
Joel

---

From: Melinda Shore <[email-masked]>
Date: Wed, 06 Nov 2013 14:33:53 -0800

> but first needs to be better understood and scoped."

Works for me.  I think a key question is whether or not
the work can be started without a rechartering.

Melinda

---

From: "Jim Guichard (jguichar)" <[email-masked]>
Date: Thu, 7 Nov 2013 14:50:30 +0000

I prefer this wording as what we are really interested in here is what
information needs to be pushed to participating SFC components to realize
a service function chain and associated service function path.

On 11/6/13 5:31 PM, "Andre Beliveau" <[email-masked]> wrote:

>Joel M. Halpern
>That still looks like application management.  In fact, it looks like the
>exact same application management you want when you are not doing service
>chaining.  Which is why I have trouble seeing how it fits in this working
>group.
>
>Yours,
>Joel
>

---

From: "Joel M. Halpern" <[email-masked]>
Date: Thu, 07 Nov 2013 11:03:43 -0500

That works for me.
Yours,
Joel