Subject: [sacm] Mirja Kühlewind's Abstain on draft-ietf-sacm-requirements-16: (with COMMENT)

From: Mirja Kühlewind <[email-masked]>
Date: Fri, 16 Jun 2017 03:19:56 -0700

Mirja Kühlewind has entered the following ballot position for
draft-ietf-sacm-requirements-16: Abstain

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COMMENT:
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I abstain because I don’t think there is a achievable value in publishing this
document in the RFC series (for consumption outside the wg). However, I also
don’t understand why there is a requirement to support multiple transport
protocols, including potentially UDP. I don’t think this is worth a discuss on
this document but if SACM plans to invent a new transport (over UDP) instead of
just using TCP which seems more than appropriate, it needs a real justification
for that (which is at least in this document not at all given)!

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From: Kathleen Moriarty <[email-masked]>
Date: Fri, 16 Jun 2017 13:16:32 -0400

Hi Mirja,

Thanks for reviewing the draft.

> https://datatracker.ietf.org/doc/draft-ietf-sacm-requirements/

I assume you are referring to the following transport requirement:

   T-005  Transport Reliability: SACM transfer protocols MUST provide
    reliable delivery of data.  This includes the ability to perform
    fragmentation and reassembly, and to detect replays.  The SACM
    transfer may take advantage of reliability features in the network
    transport; however, the network transport may be unreliable (e.g.
    UDP), in which case the SACM transport running over the unreliable
    network transport is responsible for ensuring reliability (i.e. by
    provisions such as confirmations and re-transmits).

SACM plans to re-use existing transports wherever possible and it is
likely that SNMP would be an exiting transport they will need to use
in order to collect status information from devices on the network,
hence their inclusion of this statement on UDP.  If a device supports
SNMP, YANG, or some existing collection mechanism, they will use the
supported protocol.

I hope that answers your question.  It's a complex assessment to use
standards to assess system integrity and other security properties, so
this will require using what exists and having to standardize other
options that have been in use, but need to be re-worked and
standardized (possibly OVAL plus a transport that makes sense).

Best,
Kathleen

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Best regards,
Kathleen