Subject: RE: [mpls] I-D ACTION:draft-ietf-mpls-p2mp-oam-reqs-00.txt

From: [email-masked]
Date: Wed, 21 Dec 2005 14:24:36 -0000

Authors,
Colleagues,

I have just read draft-ietf-mpls-p2mp-oam-reqs-00 for the first time and
have the following suggested edits/corrections.

Abstract - dataplane => data plane

The abstract states "may not only affect the fundamental of an MPLS
network, but also because they MAY impact service level specification
commitments for customers of their network." This sentence doesn't make
sense - may not only affect the fundamental <what?> of an MPLS network.
Also I'm not sure why the second MAY is capitalised.

In the introduction the document refers to "requirements for user and
data plane operations and management", however the term "user plane" is
never used in the rest of the document.  So I would suggest removing the
term user plane from the introduction, unless the intention is to
emphasise that user plane == data plane in which case I think this
intention needs to be made more explicit.

The introduction states "These latter are described in [MPLS-OAM] and
are not repeated in this document."  Guess this should be "These latter
requirements"

Section 4 states "The general requirements described in this section are
closely similar to those described for point-to-point MPLS in
[MPLS-OAM]." closely similar makes no sense to me - would suggest either
"closely related" or just "similar".

Section 4 states "In general, it should be noted that P2MP LSPs
introduce a scalability issue that is not present in point-to-point
MPLS."  Is this scalability issue a general one or a OAM scaling issue?
If the latter the I think you should make this explicit in the sentence
e.g. "In general, it should be noted that P2MP LSPs introduce a
scalability issue with respect to OAM that is not present in
point-to-point MPLS."

Section 4.1 states "The ability to detect defects in a broken Label
Switch Path (LSP) SHOULD not require manual hop-by-hop troubleshooting
of each LSR used to switch traffic for that P2MP LSP."  I don't like
"detect defects in a broken LSP" or "for that P2MP LSP" as the first
part of sentence doesn't mention a P2MP LSP.  Would suggest either:

"The ability to detect defects in a P2MP Label Switch Path (LSP) SHOULD
not require manual hop-by-hop troubleshooting of each LSR used to switch
traffic for that P2MP LSP.", or

"The ability to detect defects in a Label Switch Path (LSP) SHOULD not
require manual hop-by-hop troubleshooting of each LSR used to switch
traffic for a P2MP LSP."

Section 4.1 states "As the number of leaves of the P2MP LSP increases so
it becomes potentially more expensive to inspect the LSP to detect
defects."  I don't like this sentence and would suggest "As the number
of leaves of a P2MP LSP increases it potentially becomes more expensive
to inspect the LSP to detect defects."

In section 4.9 remove the superfluous "These" from the end of the first
paragraph.

Section 4.9, second paragraph - facillitate => facilitate

Section 4.11, first paragraph - matricies => matrices

Section 4.11, second paragraph - becasue => because

In section 4.11, second paragraph remove the superfluous "The" at the
beginning of the last sentence.

Section 5, first paragraph - conseuqences => consequences

Section 5, second paragraph sates "As with previous OAM function
described in [MPLS-OAM]," which doesn't read very well to me, suggest
"As with the OAM functions described in [MPLS-OAM]"

Section 5, second paragraph - becuase => because

Ben

-- 
Ben Niven-Jenkins
Network Architect, BT Exact
  
E-mail: [email-masked] 
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---

From: "Adrian Farrel" <[email-masked]>
Date: Wed, 21 Dec 2005 15:38:03 -0000

Ben,

How nice to have such a detailed review so early in the process. Thanks!

Comments bellow.

Look out for these fixes in the next revision.

Cheers,
Adrian

> Abstract - dataplane => data plane

Ack

> sense - may not only affect the fundamental <what?> of an MPLS network.

s/fundamental/fundamentals/

> Also I'm not sure why the second MAY is capitalised.

You are right. We shouldn't use RFC 2119 language in the abstract.

> intention needs to be made more explicit.

Good point. Deleted user plane from Intro and Abstract.

> are not repeated in this document."  Guess this should be "These latter

Ack

> "closely related" or just "similar".

Hah! I bet it makes some sense to you! One of the joys of being human is
that we can extract sense from our parsing of natural language ;-)

Changed to "similar".

> scalability issue with respect to OAM that is not present in

Well, both OAM and other areas. Basically, P2MP LSPs necessarily require
more of everything because they have more egresses. But, given the scope
of the I-D, your change is correct.

> Switch Path (LSP) SHOULD not require manual hop-by-hop
> troubleshooting of each LSR used to switch traffic for that P2MP
> LSP."  I don't like "detect defects in a broken LSP" or "for that
> P2MP LSP" as the first part of sentence doesn't mention a P2MP
> LSP.  Would suggest either:
>
> "The ability to detect defects in a P2MP Label Switch Path (LSP)
> SHOULD not require manual hop-by-hop troubleshooting of each
> LSR used to switch traffic for that P2MP LSP.",
> or
> "The ability to detect defects in a Label Switch Path (LSP)
> SHOULD not require manual hop-by-hop troubleshooting of
> each LSR used to switch traffic for a P2MP LSP."

Good point.
Changed to the following as LSP is already defined.
   The ability to detect defects in a P2MP LSP SHOULD not
   require manual hop-by-hop troubleshooting of each
   LSR used to switch traffic for that LSP.

> Section 4.1 states "As the number of leaves of the P2MP LSP
> increases so it becomes potentially more expensive to inspect the
> LSP to detect defects."  I don't like this sentence and would suggest
> "As the number of leaves of a P2MP LSP increases it potentially
> becomes more expensive to inspect the LSP to detect defects."

You don't like my split infinitives?

Good suggestion.

> In section 4.9 remove the superfluous "These" from the end of the first

Ack

> Section 4.9, second paragraph - facillitate => facilitate

Ack

> Section 4.11, first paragraph - matricies => matrices

Ack

> Section 4.11, second paragraph - becasue => because

Ack

> beginning of the last sentence.

Ack

> Section 5, first paragraph - conseuqences => consequences

Ack

> "As with the OAM functions described in [MPLS-OAM]"

Ack

> Section 5, second paragraph - becuase => because

Ack