[IPP] Re: Topic for IPP slides at F2F (MFD Alerts - IPP extension)

[IPP] Re: Topic for IPP slides at F2F (MFD Alerts - IPP extension)

Ira McDonald blueroofmusic at gmail.com
Mon Sep 19 14:28:13 UTC 2011


Hi Mike,

Several thoughts.

I was not a proponent a year ago of security alerts
in Printer MIB - I think they're an architectural error
and belong in an appropriate IETF Ops & Mgmt Area
MIB.

I'd rather *delete* the security alerts from this spec
(and let Common Log spec talk about them instead).

About events and transient states.  RFC 2566 and
RFC 2911 enshrined *lots* of very short-lived transient
states in printer-state-reasons (from the service level)
and defined lots or Printer MIB alert values for
printer-state-reasons.

The specific new alerts for Scanner and Fax Modem
are just as self-descriptive (and clear in my opinion)
as existing Marker and Input events.  I'll write the
sentence for each, but it won't (and inherently can't)
further qualify when to report them - the answer is:
when they occur and the implementation supports
reporting them in prtAlertTable.

If an implementation does NOT support showing
prtAlertTable content in "printer-state-reasons", then
it doesn't.

Given the terrible report/error/warning prefixes (which
are not and *could* not be IANA registered, by very their
format) from IPP/1.0 onward, the "pollution" of
printer-state-reasons with stuff of minimal value for
automated behavior is long-standing.

Comments?

Cheers,
- Ira

Ira McDonald (Musician / Software Architect)
Chair - Linux Foundation Open Printing WG
Co-Chair - IEEE-ISTO PWG IPP WG
Chair - TCG Embedded Systems Hardcopy SWG
IETF Designated Expert - IPP & Printer MIB
Blue Roof Music/High North Inc
http://sites.google.com/site/blueroofmusic
http://sites.google.com/site/highnorthinc
mailto:blueroofmusic at gmail.com
Christmas through April:
  579 Park Place  Saline, MI  48176
  734-944-0094
May to Christmas:
  PO Box 221  Grand Marais, MI 49839
  906-494-2434



On Sun, Sep 18, 2011 at 6:35 PM, Michael Sweet <msweet at apple.com> wrote:

> Ira,
>
> Given the inconsistencies I've seen in recent years with even the keywords
> defined in RFC 2911, I really think we need to provide specific descriptions
> for each new keyword, otherwise they won't get used (or won't get used
> properly).
>
> In addition, I think we want to document which new keywords are not
> appropriate for use with printer-state-reasons (even if they have to be
> registered for that attribute), simply because some are not
> persistent/present state but instead are really identifiers for sporadic
> events.  We don't want "idiot lights" that need to be reset, and we don't
> want clients that poll the printer on the off chance they'll see a
> particular keyword show up in printer-state-reasons because the printer
> chose not to support printer-alerts.
>
> (and FWIW I think we want IPP Everywhere to require printer-alert and
> printer-alert-description...)
>
> On Sep 16, 2011, at 9:47 AM, Ira McDonald wrote:
>
> Hi Mike,
>
> Sure I can add a brief description for each new alert code.
>
> But I note that this has never been done before in either IPP PSX
> or Printer MIB itself (arguably a Printer MIB deficiency).
>
> Note that, by IPP PSX precedent, ALL IANA Printer MIB alert codes
> are available in the REQUIRED "printer-state-reasons" attribute (by
> direct transform from the IANA Printer MIB registry).
>
> This supports wider interoperability with IPP implementations that don't
> implement the "printer-alert" attribute (keyword/value pairs).
>
> That is, it's an implementation choice to show specific alert conditions
> in "printer-state-reasons" - which already has a *complete* set defined
> for the Printer MIB and Finisher MIB subunits).
>
> Security Alerts:
>
> I'm happy to explain these - due to copyright, we can't actually use
> the IEEE 2600 definitions - though we can mention IEEE 2600 as an
> informative reference - normative references to non-public specs are
> not allowed by PWG process and precedent.
>
> Cheers,
> - Ira
>
>
> Ira McDonald (Musician / Software Architect)
> Chair - Linux Foundation Open Printing WG
> Co-Chair - IEEE-ISTO PWG IPP WG
> Chair - TCG Embedded Systems Hardcopy SWG
> IETF Designated Expert - IPP & Printer MIB
> Blue Roof Music/High North Inc
> http://sites.google.com/site/blueroofmusic
> http://sites.google.com/site/highnorthinc
> mailto:blueroofmusic at gmail.com
> Christmas through April:
>   579 Park Place  Saline, MI  48176
>   734-944-0094
> May to Christmas:
>   PO Box 221  Grand Marais, MI 49839
>   906-494-2434
>
>
>
> On Thu, Sep 15, 2011 at 11:51 PM, Michael Sweet <msweet at apple.com> wrote:
>
>> On Sep 15, 2011, at 11:05 AM, Ira McDonald wrote:
>>
>> Hi Mike,
>>
>> I'd like to add to the IPP slide deck discussion of the MFD Alerts
>> for Printer MIB spec which has just had its second review at
>> Prototype status:
>>
>>
>> Will do.
>>
>> ...
>>
>> Will CUPS pickup the IANA IPP Registry keywords for scanner, fax
>> modem, and security alerts in IPP printer-state-reasons attribute?
>>
>>
>> CUPS already supports arbitrary keywords from drivers, so a fax driver
>> definitely could set them today.
>>
>> Scanning is not currently supported via CUPS, so that will have to wait
>> for a future implementation.
>>
>> As for the security keywords, I will need to review them closely; it isn't
>> clear that mapping them all to printer-state-reasons makes sense since they
>> represent events (alerts) and not persistent conditions.
>>
>> Moreover, I think all of the keywords need at least a sentence to describe
>> what they mean (it is not obvious to me, particularly for the security
>> keywords)
>>
>>  __________________________________________________
>> Michael Sweet, Senior Printing System Engineer, PWG Chair
>>
>>
>
> __________________________________________________
> Michael Sweet, Senior Printing System Engineer, PWG Chair
>
>

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