[Dime] Adam Roach's No Objection on draft-ietf-dime-rfc4006bis-08: (with COMMENT)

[Adam Roach <[e-mail]>]

Adam Roach has entered the following ballot position for
draft-ietf-dime-rfc4006bis-08: No Objection

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COMMENT:
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Thanks to the authors and other participants who helped with this revision of
the credit-control application. Thanks in particular for the addition of an
extensive privacy considerations section.

I will note that I only reviewed the diffs between this document and RFC 4006.

I have a handful of comments.

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General nit:

This document uses the term "service specific" as a compound adjective in
several places. As a compound adjective, this should be hyphenated (i.e.,
"service-specific").

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§1.1:

This document uses lowercase forms of RFC-2119-defined terms. Please update this
section to use the boilerplate from RFC 8174.

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§5.1.2:

>  If independent credit-control of multiple services is used, the
>  Validity-Time AVP and Final-Unit-Indication AVP or QoS-Final-Unit-
>  Indication AVP SHOULD be present either in the Multiple-Services-
>  Credit-Control AVP(s) or at command level as single AVPs.

The phrasing here is ambiguous -- it's not clear whether the requirement is:

  (Validity-Time and Final-Unit-Indication) or QoS-Final-Unit-Indication

... or ...

  Validity-Time and (Final-Unit-Indication or QoS-Final-Unit-Indication)

I suspect it's the latter, in which case I suggest:

   If independent credit-control of multiple services is used, the
   Validity-Time AVP, and either the Final-Unit-Indication AVP or
   the QoS-Final-Unit-Indication AVP, SHOULD be present either in the
   Multiple-Services- Credit-Control AVP(s) or at command level as single
   AVPs.

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§5.2.1:

The alignment of the "Diameter AAA Server" title on Figure 3 has changed from
RFC 4006 in a way that looks worse.

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§5.6.2:

>  The credit-control
>  client receives a Credit-Control-Answer or service specific
>  authorization answer with the Final-Unit-Indication or the QoS-Final-
>  Unit-Indication AVP and Validity-Time AVPs but no Granted-Service-
>  Unit AVP.

This has the same confusion as above regarding the application of logical
combinations. The second half of the statement is of the form "A or B and C
but not D," which is pretty ambiguous. It's also a little unclear whether the
client receives a Credit-Control-Answer (with A or B and C but not D), or just
a Credit-Control-Answer of any description, full stop.

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§8.19

>  Note: The values reported in a Used-Service-Unit AVP does not
>  necessarily have a relation to the grant provided in a Granted-
>  Service-Unit AVP, e.g., the value in this AVP may exceed the value in
>  the grant.

Nit: "...values reported in a Used-Service-Unit AVP do not..."
                                                    ^^

(or "...value... does not...")

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§8.54:

>  The User-Equipment-Info-MAC (AVP Code TBD3) is of type OctetString.
>  The User-Equipment-Info-MAC AVP contains the 48-bit MAC address is
>  formatted as described in [RFC3580].

Nit: remove "is" after "address".

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§8.65:

>  The Redirect-Address-IPAddress AVP (AVP Code TBD14) is of type
>  Address and defines the IPv4 or IPv6 address of the redirect server
>  with which the end user is to be connected when the account cannot
>  cover the service cost.

This appears to be underspecified, unless I've missed some specification
elsewhere regarding what the client is supposed to do with this IP address.
While the other redirection methods (HTTP, SIP) have relatively clear means of
contact (they indicate a protocol), the indication of only an IP address with
neither protocol nor port doesn't seem to provide enough information for a
client to act on.  Please either flesh this out in this section, or point to
another document that indicates how this IP address is to be used.

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§12:

When new documents obsolete an RFC that originally registered values with IANA,
I'm used to seeing that document also update the IANA registry so that the
corresponding entries now point to the new document. You may consider text that
instructs IANA to update the existing RFC-4006-registered values so that they
point to this document instead of RFC 4006.

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Appendix B:

As a general comment for all of the examples: I'm surprised that none of the
examples have been updated to reflect the newly defined capabilities in this
document. For example, all the examples in this appendix use
Final-Unit-Indication rather than QoS-Final-Unit-Indication. In practice, to
show maximally flexible and compatible examples, I would expect that the
examples would include both AVPs. This applies to all of the "Extension"
AVPs as well.

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Appendix B.2:

>  control server.  Therefore, in this example, it is assumed that the
>  SIP Proxy adds a Record-Route header in the initial SIP INVITE

"...a Record-Route header field..."

(A SIP header is everything before the first blank line; individual lines within
a SIP header are called "header fields")