PMP Mail Archive: Re: PMP> Charts for Austin PMP meeting

PMP Mail Archive: Re: PMP> Charts for Austin PMP meeting

Re: PMP> Charts for Austin PMP meeting

JK Martin (
Sun, 30 Mar 1997 15:52:22 -0500 (EST)


> "Done" means that the justification has been written.

Ah, I see now. Being the "sponsor" for the new "prtGeneralPrinterName"
object (even though Harry is listed on your chart), I had already posted
the justification for the new object.

This object was discussed in rabid detail during the Portland meeting
last July, as I recall. The original message describing the problem
for which this object was designed is attached to this message. If
the attached text is not sufficient for a "justification", then let
me know and I'll be more than happy to quickly craft some other text.


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Date: Wed, 3 Jul 96 10:52 EDT
From: (JK Martin)
Subject: How to discriminate between multiple printers?

This issue has probably arisen before (I hope), so perhaps someone
can give me some pointers or copies of relevant email messages.

The question is: How can a mgmt app distinguish between multiple
printers represented by multiple instances of RFC1759 in the Host
Resources MIB?

What I'm looking for is sort of "administrative name" that would allow
an SNMP application to target a specific instance of the printer in
the HR MIB for a given host.

A similar data element is present in MIB-II (sysName), where the MIB
guidelines state that its value should be the "fully qualified network
name" assigned to the host. That seems ok, but what if one or more
printers registered in the hrDeviceTable is not physically attached
to the host, but rather exists as its own network entity (with or
without embedded SNMP support)?

For "typical" implementations of a network printer with RFC1759 support,
we (Underscore) expect the manufacturer to have one and only one entry
in the hrDeviceTable with a device type of "printer"; the index value
for the first such entry found in the table is then used in all SNMP
references to the printer.

However, as we all know, the HR MIB was designed to support multiple
instances of printers. While such support is probably a bit rare
right now, I'll bet that Jay Cummings' efforts with NDPS environment
does exactly that (right, Jay?).

Obviously our "single entry only" approach in resolving the target printer
device index will fail in an environment where multiple printers are
registered in the HR MIB.

But how can an SNMP app truly distinguish a target printer from an
administrative point of view (ie, a unique instance name)?

Any thoughts/ideas are greatly appreciated. If we are unable to solve
this problem, then our SENSE software demo will not be able to support
more than one printer in the NDPS environment at the bake-off.

And that's only the tip of the iceberg...


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