Subject: tsv-dir review of draft-ietf-mpls-p2mp-lsp-ping

From: "SCHARF, Michael" <[email-masked]>
Date: Sun, 29 May 2011 10:46:33 +0200

Hello,

I've reviewed this document as part of the transport area directorate's
ongoing effort to review key IETF documents. These comments were written
primarily for the transport area directors, but are copied to the
document's authors for their information and to allow them to address
any issues raised. The authors should consider this review together with
any other last-call comments they receive. Please always CC
[email-masked] if you reply to or forward this review.

Disclaimer: Please note that I am a transport protocol researcher and
thus not familiar with details of the MPLS OAM mechanisms.

This draft is basically ready for publication, but there is an issue
that should be fixed before publication. 

Content:
--------

The LSP ping relies on the "Echo Jitter TLV" to deal with the implosion
of feedback messages, which is important in order to avoid congestion.
However, there seems to be a SHOULD/MUST mismatch concerning the
required reaction:

- Section 3.3: "A responding node SHOULD wait a random amount of time
between zero milliseconds and the value specified in this field."

- Section 4.1.2: "If this TLV is present, the responding LSR MUST delay
sending a response for a random amount of time between zero milliseconds
and the value indicated in the TLV."

Editorial:
----------

Section 4.2.1.3:  s/like an combination/like a combination/

Best regards

Michael

---

From: "Adrian Farrel" <[email-masked]>
Date: Sun, 29 May 2011 18:03:16 +0100

Excellent catch Michael!

Looks like that has been in place since the earliest text on jitter.

I'm going to suggest that it exists because 3.3 tries to cover all cases, where
4.1.2 separates P2MP and P2P cases. But it isn't a very convincing argument, and
the text needs to be fixed.

Cheers,
Adrian

> -----Original Message-----
> From: SCHARF, Michael [mailto:[email-masked]]
> Sent: 29 May 2011 09:47
> To: [email-masked]
> Cc: [email-masked]; [email-masked]; [email-masked]
> Subject: tsv-dir review of draft-ietf-mpls-p2mp-lsp-ping
> 
> Hello,
>

---

From: "Shaleen Saxena (ssaxena)" <[email-masked]>
Date: Sun, 29 May 2011 23:32:27 -0500

Hi Michael, Adrian,

Thanks for the comments. I will update the document at the earliest and
send it out to all the authors before uploading the new version.

Regards,
Shaleen

-----Original Message-----
From: Adrian Farrel [mailto:[email-masked]] 
Sent: Sunday, May 29, 2011 1:03 PM
To: 'SCHARF, Michael'; [email-masked]
Cc: [email-masked]; [email-masked]; [email-masked]
Subject: RE: tsv-dir review of draft-ietf-mpls-p2mp-lsp-ping

Excellent catch Michael!

I'm going to suggest that it exists because 3.3 tries to cover all
cases, where
4.1.2 separates P2MP and P2P cases. But it isn't a very convincing
argument, and
the text needs to be fixed.

Cheers,
Adrian