Subject: Re: Proposed BFD WG

From: Pekka Savola <[email-masked]>
Date: Wed, 24 Mar 2004 09:00:21 +0200 (EET)

Two comments to the proposed charter..

On Mon, 22 Mar 2004, Alex Zinin wrote:
> 2. Document BFD encapsulation and usage profile for single-hop IPv4 and IPv6
>     adjacencies and submit the specification to the IESG for publication as
>     a Proposed Standard.

This takes no stance on which protocols this would be run.  I.e., we 
must specify how to configure the usage for adjacencies in a certain 
protocol.  (Like, OSPFv2, OSPFv3, IS-IS, eBGP, ....)

Is this worth spelling out?

> 3. Document BFD encapsulation and usage profile over Ethernet (IEEE 802.3 and
>     Ethernet_II) and submit the specification to the IESG for publication as a
>     Proposed Standard.

I'm not sure how this relates to the forming of adjacencies.  
Certainly, it would be very useful to run just one instance of BFD 
over Ethernet -- so that in case you'd run multiple protocols over the 
same media, you need only one set of hello mechanisms -- but I don't 
know how this relates to the adjancency establishment and the rest of 
the BFD framework.  Maybe need a bit of clarifying here.
  
-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

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From: Rahul Aggarwal <[email-masked]>
Date: Wed, 24 Mar 2004 00:16:02 -0800 (PST)

Hi Pekka,

> Is this worth spelling out?

As long as a protocol or application can bootstrap a BFD
session over IP, there should be no limitation on which protocols can be
run. If there are specific bootstrapping details, that can help in
inter-operability they should be spelled out. I am assuming that 'usage
profile' implies that..

> the BFD framework.  Maybe need a bit of clarifying here.

Again it seems that 'usage profile' captures the above..

rahul

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From: Pekka Savola <[email-masked]>
Date: Wed, 24 Mar 2004 11:08:05 +0200 (EET)

On Wed, 24 Mar 2004, Rahul Aggarwal wrote:
> run. 

Right.

> If there are specific bootstrapping details, that can help in

But as you say, there are likely some details to bootstrapping which 
should be spelled out.

The point is, do we want to state in charter which protocols (at 
least) should have usage profiles?  Do we leave it empty?  Do we rule 
out some protocols from usage profiles?

> Again it seems that 'usage profile' captures the above..

Except that protocols typically do not exchange adjcacencies between
Ethernet addresses -- so this appears to be independent of the
adjacency forming process.

Or are you saying, "usage profile for BFD over Ethernet between
manually configured end-points" ?

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From: Rahul Aggarwal <[email-masked]>
Date: Wed, 24 Mar 2004 11:29:49 -0800 (PST)

Hi Pekka,

[snip]

> out some protocols from usage profiles?

Imho this is a detail that can be worked out when the WG discusses the BFD
over IPv4 document. Bootstrapping details can be added where they seem
necessary. Don't think the charter needs to spell it out..

> adjacency forming process.

There is no assumption here that IP protocols are running over the
Ethernet links. BFD over ethernet can be used between a router and an
ethernet switch, for example.

> manually configured end-points" ?

I am saying that bootstrapping mechanims are application specific, whether
for BFD for IPv4, ethernet etc. They should certainly be spelled out when
needed and it can be done as part of completing the encap/usage profile
spec..

rahul

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From: Pekka Savola <[email-masked]>
Date: Thu, 25 Mar 2004 08:55:10 +0200 (EET)

> necessary. Don't think the charter needs to spell it out..

You said "over IPv4" but you meant "over IP", I hope.  Any work that 
would start with only IPv4 would be completely inappropriate.

IMHO, this is probably an important point.  If we don't know any
protocols we'd like to rule out right now, they should be listed
there.  On the other hand, listing the protocols which we should AT
LEAST work on would be equally useful; for example, the list could be
at least: IS-IS (both IPv4 and IPv6), OSPFv2, OSPFv3, eBGP, {static
routes}.

That would give the reader of the charter a better picture of what 
we're (at least) trying to solve.

> ethernet switch, for example.

(OK; I mistunderstood this.  I think the charter needs to be more 
specific what the action item means in practice.)

Sorry for misunderstanding.  But again, as above, it would be 
appropriate to describe this context.  Which adjacency-forming 
protocol are you running between a router and switch which would be 
used to trigger these BFD adjacencies?  If you don't configure these 
manually, that's a key point here.

> needed and it can be done as part of completing the encap/usage profile

Yep -- these certainly will be worked at, but trying to figure out 
what _at least_ is in scope would be highly useful -- rather than 
leaving this unspecified, blank.