From: wamwagner@comcast.net
Date: Thu Feb 16 2006 - 11:56:27 EST
I agree that inconsistent and incorrect Printer MIB implementations are rampant, and possibly dealing with these increases the inefficiency of management applications. Ira's suggestion that interoperability testimg as a prerequisite would be helpful in exposing these inappropriate implementations, at least to the products' manufacturers.
This may or may not have an effect. I beleive that most printer MIB inconsistencies are not a result of misunderstanding the standard, but a result of intentional decisons either to not invest the expense in doing it right or to willfully obfuscate access to certain attributes to encourage the use of the manufacturer's proprietary solutions.
Also, some of the very inefficient SNMP interactions I have observed are between applications and printers from the same manufacturer, where the application engineers presumably know the specifics of the MIB implementations. Although this may be a result of internal miscommunication or the intentional use of arcane private MIBS for product differentiation, I suspect that the effect on products' performance is just not recognized or is not a concern.
In short, I think the problem is that it is not clear to the manufacturers that the benefits to them of having:
1. good standard MIB implementations allowing effective management by any proper application, and
2. mangement applications that are efficient with all properly impelmeted MIBs
outweigh the benefits of having possible proprietary advanatges for their own products. Indeed, until users recognize the benefits of and demand consistent standardized management capabilities, there probably is no advanatge to manufacturers in implementing them.
Bill Wagner, TIC
-------------- Original message --------------
From: "McDonald, Ira" <imcdonald@sharplabs.com>
> Hi,
>
> First, the primary purpose of _any_ implementors guide
> is to foster interoperable, consistent implementations.
>
> Second, a Printer MIB v2 interoperability testing event
> is a necessary prerequisite to any well-grounded effort
> to produce a PWG Printer MIB Implementors Guide, IMHO.
>
> Third, efficiency is largely in the "eye of the beholder".
>
> Fourth, excellent books and articles already exist about
> how to do efficient SNMP (and more generally, management
> protocol) implementations. The PWG members are not (with
> rare exceptions) subject matter experts here. A section
> in the proposed PWG Printer MIB Implementors Guide that
> identifies good SNMP and other management software design
> references would be sufficient and appropriate.
>
> Cheers,
> - Ira
>
>
> Ira McDonald (Musician / Software Architect)
> Blue Roof Music / High North Inc
> PO Box 221 Grand Marais, MI 49839
> phone: +1-906-494-2434
> email: imcdonald@sharplabs.com
> -----Original Message-----
> From: Paul Tykodi [mailto:ptykodi@tykodi.com]
> Sent: Thursday, February 16, 2006 9:18 AM
> To: 'Harry Lewis'
> Cc: pmp@pwg.org; 'Bergman, Ron'; 'McDonald, Ira'
> Subject: RE: Feedback - PMP> Minutes of the MFP Teleconference 20060214
>
>
> Hi,
>
> I believe the two concepts may actually work together to cause difficulties.
> The case I am thinking about is where a software product is developed, which
> makes an assumption that all Printer MIB implementations will provide a
> particular response to a certain question given a particular condition
> exists within the device, and the assumption turns out to be false. Each
> time the software encounters a situation where the design assumption turns
> out to be incorrect (device returns some unexpected response from the
> perspective of the software), the possibility exists for significantly
> increased SNMP traffic because the software needs to learn more about the
> condition of the device in order to decide whether to continue the operation
> currently being processed.
>
> Thus I believe we could probably link the two concepts together in one
> document should the PWG consensus be that this idea was the best option to
> pursue.
>
> Best Regards,
>
> /Paul
> --
> Paul Tykodi
> Principal Consultant
> TCS - Tykodi Consulting Services LLC
>
> Tel/Fax: 603-343-1820
> Mobile: 603-866-0712
> E-mail: ptykodi@tykodi.com
> WWW: http://www.tykodi.com
>
>
>
> From: Harry Lewis [mailto:harryl@us.ibm.com]
> Sent: Thursday, February 16, 2006 2:14 AM
> To: McDonald, Ira
> Cc: pmp@pwg.org; ptykodi@tykodi.com; 'Bergman, Ron'
> Subject: RE: Feedback - PMP> Minutes of the MFP Teleconference 20060214
>
>
> Inconsistency is a more serious problem (in my experience) than efficiency
> (which I THINK is Paul's hot button). I think it would be great if we
> addressed both, but these may require separate efforts.
> ----------------------------------------------
> Harry Lewis
> IBM STSM
> Chairman - IEEE-ISTO Printer Working Group
> http://www.pwg.org
> IBM Printing Systems
> http://www.ibm.com/printers
> 303-924-5337
> ----------------------------------------------
>
>
> "McDonald, Ira"
> Sent by: pmp-owner@pwg.org
> 02/15/2006 08:04 PM To"'Bergman, Ron'" ,
> ptykodi@tykodi.com, pmp@pwg.org
> cc
> SubjectRE: Feedback - PMP> Minutes of the MFP Teleconference 20060214
>
>
>
>
>
>
>
>
> Hi,
>
> I spoke with Rick Landau (Dell) this afternoon and he's getting
> some input from Dell management software implementors who have
> observed implementation inconsistencies in Printer MIB - he said
> he'll pass these along pretty soon - I think that cross-vendor
> management software implementors are some of the best allies for
> a PWG Best Practices document on the Printer MIB.
>
> Note that the PWG Process/2.0 requires that Implementors Guides
> be subject to the full process and Formal Approval and final
> publication as Best Practices in '/pub/pwg/informational'
> (i.e., unlike IETF Implementors Guides they are NORMATIVE).
>
> Cheers,
> - Ira
>
>
>
> Ira McDonald (Musician / Software Architect)
> Blue Roof Music / High North Inc
> PO Box 221 Grand Marais, MI 49839
> phone: +1-906-494-2434
> email: imcdonald@sharplabs.com
>
> > -----Original Message-----
> > From: pmp-owner@pwg.org [mailto:pmp-owner@pwg.org]On Behalf
> > Of Bergman,
> > Ron
> > Sent: Wednesday, February 15, 2006 12:37 PM
> > To: ptykodi@tykodi.com; pmp@pwg.org
> > Subject: RE: Feedback - PMP> Minutes of the MFP
> > Teleconference 20060214
> >
> >
> > Hi Paul,
> >
> > I have also observed poorly designed SNMP based applications
> > that consume
> > enormous amounts of network bandwith. For example, reading
> > large portions
> > of the input and output tables at a fairly high frequency to
> > determine the
> > available paper sources and destinations. In many cases I
> > believe this is
> > the result of a desire to simplify the application, through
> > the use of a
> > single query loop, by developers that are not experienced in
> > real-time code
> > practices.
> >
> > As chairman of the PWG MIBs Working Group I would be glad to
> > work with you
> > to define and present this as a project proposal to the PWG.
> >
> > Regards,
> > Ron Bergman
> >
> >
> > -----Original Message-----
> > From: pmp-owner@pwg.org [mailto:pmp-owner@pwg.org]On Behalf Of Paul
> > Tykodi
> > Sent: Wednesday, February 15, 2006 6:13 AM
> > To: pmp@pwg.org
> > Subject: RE: Feedback - PMP> Minutes of the MFP
> > Teleconference 20060214
> >
> >
> > Hi Ira,
> >
> > I am willing to be a co-editor for such a project. Is this
> > something the PWG
> > would likely want to pursue in the near term future?
> >
> > Thanks.
> >
> > Best Regards,
> >
> > /Paul
> > --
> > Paul Tykodi
> > Principal Consultant
> > TCS - Tykodi Consulting Services LLC
> >
> > Tel/Fax: 603-343-1820
> > Mobile: 603-866-0712
> > E-mail: ptykodi@tykodi.com
> > WWW: http://www.tykodi.com
> >
> > -----Original Message-----
> > From: pmp-owner@pwg.org [mailto:pmp-owner@pwg.org] On Behalf
> > Of McDonald,
> > Ira
> > Sent: Wednesday, February 15, 2006 1:06 AM
> > To: 'ptykodi@tykodi.com'; pmp@pwg.org
> > Subject: RE: Feedback - PMP> Minutes of the MFP
> > Teleconference 20060214
> >
> > Hi Paul,
> >
> > Harry Lewis (IBM, chair of PWG) has repeatedly suggested that a
> > good project would be a PWG standard "Printer MIB Implementor's
> > Guide" - similar in purpose and scope to the IETF Proposed Std
> > "IPP/1.1 Implementor's Guide" (RFC 3196, November 2001).
> >
> > Volunteer PWG editor bandwidth is the problem - that and the very
> > complicated problem space of SNMP optimization biased by MIB
> > optimization biased by the fact that printers (and spoolers) are
> > supposed to "print first and bother me later".
> >
> > A first step was that Printer MIB v2 (RFC 3805) contained a great
> > many improved DESCRIPTION clauses that clarified and recommended
> > implementation choices for many of the columnar objects.
> >
> > But the problem you've identified is a whole system problem, not
> > just a Printer MIB implementation problem.
> >
> > Cheers,
> > - Ira (co-editor of Printer MIB v2)
> >
> > Ira McDonald (Musician / Software Architect)
> > Blue Roof Music / High North Inc
> > PO Box 221 Grand Marais, MI 49839
> > phone: +1-906-494-2434
> > email: imcdonald@sharplabs.com
> >
> > -----Original Message-----
> > From: pmp-owner@pwg.org [mailto:pmp-owner@pwg.org]On Behalf
> > Of Paul Tykodi
> > Sent: Tuesday, February 14, 2006 10:50 PM
> > To: pmp@pwg.org
> > Subject: RE: Feedback - PMP> Minutes of the MFP
> > Teleconference 20060214
> >
> >
> > Dear Bill,
> >
> > The host I was most recently analyzing was an IBM iSeries -
> > AS/400 host. The
> > MIB itself worked flawlessly. I am not suggesting that it was
> > somehow the
> > culprit for the slow printing or that it did not work correctly. The
> > communication started OK and then the host was concerned that
> > a response
> > packet was not received in a timely fashion. It began a
> > significant SNMP
> > based questioning process to determine the current hardware
> > status of the
> > device and interspersed with the SNMP questions about whether
> > the device was
> > in error or not came a re-transmission of a potentially lost
> > packet just to
> > be safe.
> >
> > Pretty soon the majority of the communication on the wire
> > revolved around
> > SNMP discussions as to the device's status and data packet
> > re-transmissions
> > and confirmations from the printing device that it had indeed
> > received the
> > packet re-transmissions. As you mention, the whole idea of printing
> > information had become unfortunately a secondary concern.
> >
> > In the end, all of the data was printed and no errors were
> > reported by the
> > host. Unfortunately the method utilized to determine that
> > everything was
> > actually fine was so intrusive on the printing process that I feel
> > comfortable saying I believe that a typical customer (having
> > paid a fee for
> > their printing device related to its rated engine performance) would
> > probably not have accepted the result as commercially viable.
> >
> > So my previous comment is directed more towards device
> > managing software
> > product's use of MIB capabilities (especially if more
> > interesting things to
> > check are added into future MIB's) and the impact that
> > significant device
> > status verifications can have on the actual process (in this
> > case printing),
> > which is being monitored.
> >
> > Thus in the future if some type of RFC or other standards
> > document were to
> > be produced, my suggestion would be to include some examples
> > that tried to
> > help steer software developers implementing use of MIB data away from
> > creating the issue you outline in point b. below.
> >
> > Thanks.
> >
> > Best Regards,
> >
> > /Paul
> > --
> > Paul Tykodi
> > Principal Consultant
> > TCS - Tykodi Consulting Services LLC
> >
> > Tel/Fax: 603-343-1820
> > Mobile: 603-866-0712
> > E-mail: ptykodi@tykodi.com
> > WWW: http://www.tykodi.com
> >
> >
> >
> > From: pmp-owner@pwg.org [mailto:pmp-owner@pwg.org] On Behalf Of
> > wamwagner@comcast.net
> > Sent: Tuesday, February 14, 2006 10:33 PM
> > To: ptykodi@tykodi.com; pmp@pwg.org
> > Cc: Paul Tykodi
> > Subject: RE: Feedback - PMP> Minutes of the MFP
> > Teleconference 20060214
> >
> > Paul,
> >
> > Thanks for sending in your observation. I have worked with
> > printers and SNMP
> > management for many years and have not seen anything like the sort of
> > slowdown that you cite. Perhaps this is because I have worked
> > with slower
> > machines and printers/MFPs with separate NICs. At any rate, a
> > basic SNMP
> > tenet is that servicing of SNMP is secondary to the main
> > purpose of the
> > device. Indeed, reflecting this, I have seen missed or late
> > SNMP responses
> > during periods of high print activity.
> >
> > Of course, it is desirable to have efficient MIBs, something
> > that sometimes
> > gets lost in this era of "human readability". Although you may have
> > contradicting data, I would suggest that the current public
> > MIBs are not in
> > themselves inefficient and that the problem you observed may
> > be due to other
> > factors such as:
> > a. certain private MIBS use an indirect addressing approach,
> > particularly for writes, which may make for some elegance but does
> > complicate interaction
> > b. many management applications are terribly
> > inefficient, repeatedly
> > querying the same (sometimes status) variable, and often unnecessarily
> > dumping blocks of data.
> > c. Drastically underpowered controllers and/or poor handling of
> > priorities
> >
> > Although I understand that it may be difficult to release
> > such information,
> > it would be useful to have some information on the specifics of the
> > slow-down... the condition the management station was
> > querying, the objects
> > being queried, etc.
> >
> > Bill Wagner, TIC
> >
> > -------------- Original message --------------
> > From: "Paul Tykodi"
> > Dear List,
> >
> > During the last year, I have been involved in some network
> > analysis looking
> > at how certain hosts use the current printer MIB to determine
> > device status
> > (including that of MFP's) and what effect a significant number of SNMP
> > queries and responses can have on effective printing
> > throughput (at times
> > rather dramatic reduction in achievable throughput).
> >
> > In looking at the minutes from today's meeting, I would
> > suggest that it
> > might be a good idea to consider whether MIB optimization should be a
> > category for an MFP alerts project. The idea would be to at
> > least minimally
> > describe some best practices for MIB usage, which would
> > result in the host
> > obtaining the required information using the smallest SNMP query and
> > response packet transmission overhead possible.
> >
> > In case people are wondering how dramatic a reduction in PPM
> > I have observed
> > when SNMP traffic is significant (host trying to determine
> > whether device is
> > in error or not - multiple queries are sent asking more and
> > more specific
> > questions of the printer MIB), I have seen printers and MFP's
> > with rated
> > speeds in the 75 - 125 PPM range reduced to achieving actual
> > throughput in
> > the 10 to 20 PPM range.
> >
> > HTH
> >
> > Best Regards,
> >
> > /Paul
> > --
> > Paul Tykodi
> > Principal Consultant
> > TCS - Tykodi Consulting Services LLC
> >
> > Tel/Fax: 603-343-1820
> > Mobile: 603-866-0712
> > E-mail: ptykodi@tykodi.com
> > WWW: http://www.tykodi.com
> >
> >
> >
> > From: pmp-owner@pwg.org [mailto:pmp-owner@pwg.org] On Behalf
> > Of Bergman, Ron
> > Sent: Tuesday, February 14, 2006 7:02 PM
> > To: pmp@pwg.org
> > Subject: PMP> Minutes of the MFP Teleconference 20060214
> >
> > The minutes can be found at:
> >
> > ftp://ftp.pwg.org/pub/pwg/pmp/minutes/mfp/MFP_Minutes_20060214.pdf
> > Ron Bergman
> > Chairman, Printer MIBs Working Group
> >
> >
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