RE: Gen-ART LC Review of draft-ietf-mptcp-api-05

<philip.eardley@bt.com> Mon, 13 August 2012 14:14 UTC

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From: <philip.eardley@bt.com>
To: <ben@nostrum.com>, <draft-ietf-mptcp-api.all@tools.ietf.org>
Date: Mon, 13 Aug 2012 15:14:06 +0100
Subject: RE: Gen-ART LC Review of draft-ietf-mptcp-api-05
Thread-Topic: Gen-ART LC Review of draft-ietf-mptcp-api-05
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Ben,
Thanks for your review. 

The right status isn't clear-cut (I think), but when we (Chairs & Wes) discussed it, Info seemed best
* mainly because precedent seems to be that API docs are informational, for example socket API extensions for SCTP http://datatracker.ietf.org/doc/rfc6458/  
* also the doc has two main parts - looking at the impact that MPTCP may have on application performance - and describing a basic API for MPTCP-aware applications. The first part seems clearly Informational. So if the API part is not Info, there is the effort of splitting the doc. Pragmatically I think this should only be done if clearly needed.

I'm afraid I don't know case history of how the IETF tries to extend non-IETF standards.

On the status of Posix reference, which appears twice in the doc
>> The abstract specification is in line with the
   Posix standard [17] as much as possible
>> One commonly used TCP socket option (TCP_NODELAY) disables the Nagle
   algorithm as described in [2].  This option is also specified in the
   Posix standard [17].  

The guidance:
>> Normative references specify documents that must be read to understand or implement the technology in the new RFC, or whose technology must be present for the technology in the new RFC to work.

On its second appearance, I think [17] is definitely being used informatively.
The first appearance is less clear  cut, I think. Am inclined to say this is still informative - it's just explaining the style adopted for the abstract specification (if [17] changed then it wouldn't be necessary to change this doc).

Thanks also for the nits

Best wishes
phil



-----Original Message-----
From: Ben Campbell [mailto:ben@nostrum.com] 
Sent: 10 August 2012 20:31
To: draft-ietf-mptcp-api.all@tools.ietf.org
Cc: General Area Review Team; IETF Discussion List
Subject: Gen-ART LC Review of draft-ietf-mptcp-api-05

I am the assigned Gen-ART reviewer for this draft. For background on
Gen-ART, please see the FAQ at

<http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq> .

Please resolve these comments along with any other Last Call comments
you may receive.

Document:  draft-ietf-mptcp-api-05

Reviewer: Ben Campbell
Review Date: 2012-08-10
IETF LC End Date: 2012-08-14

Summary: This draft is almost ready for publication, but I have questions about its intended informational status.

Major issues: None

Minor issues:

-- Section 5 specifies an abstract "basic" API for MPTCP. The draft characterizes this as an extension to the sockets API. On it's face, this sounds like it's creating a standard, or will at least have the effect of creating a standard. Is that the intent? If so, I wonder why the intended status is informational rather than standards track? If not, it would be useful to explicitly state the intent. (For example, is this intended as an input to inform a standardization effort?)

I realize that the sockets API is not an IETF standard. I don't know if that is part of the reason for making this draft informational, nor am I familiar with precedent for extending non-IETF-native standards. But at the risk of attacking a straw man, I am concerned that putting something that could be interpreted as a "standard" in an informational RFC might not be the best practice for solving that sort of process issue.


-- It seems like at least passing knowledge of the sockets API is needed to understand this document. I'm curious why the POSIX reference is informational rather than normative?

Nits/editorial comments:

-- 3.3.1, 1st paragraph: "This will provide greater bandwidth for an application. "

I assume this means "as great or greater", given the previous statements that MPTCP should be at worst no worse than normal TCP?

-- 3.2.1, 1st paragraph: "...while having TCP SYN/ACK ready to reply to..."

I had to think about this a while to figure out the meaning. Perhaps it could be rephrased?