Thank you, Rick, for that complete statement which pretty much states the
basis for the WIMS/CIM activity. I would make a few more observations:
- Even if/when WS-Man becomes more popularly used, SNMP is not
going away for a long time and there will be a prolonged period of
supporting both management protocols. By basing the CIM Print management
elements on well established and implemented MIB objects, the CIM Printer
o Allows early support of printer management via WS-Man by using software
or network appliance SNMP to WS-Man converters, so that printers that just
support SNMP can still be monitored via WS-Man.
o Allows use of a common management information base in the printer that
the two management protocols can both draw upon.
- Although this approach allows monitoring via WS-Man pretty much
to the same degree as with the standard Printer MIB sets, at this point it
does not address the additional features of modern printers that are not
covered in the traditional MIBs.
o This deficiency will be alleviated somewhat by the current activity to
render the Imaging System Counter MIB objects in CIM format
o Hopefully, there will be additional PWG work to recast service and job
elements in IPP and in other MIBs into CIM format
o We envision an effort to eventually enrich the CIM imaging libraries
with additional MFD oriented elements
Of course, this all takes work in selecting and defining management
elements, in formatting the information appropriately, and in going through
the standardization steps. Rick and Ira have beaten something of a path to
follow and have offered to provide guidance to those who would continue this
effort. The objective would be to provide adequate standard management
capability for imaging devices via WS-Man, avoiding the Balkanizing that has
occurred with the plethora of private MIBs. In the last analysis, this
would save significant effort both for manufacturers and management
providers, and ultimately would benefit the customers as well (perhaps
encouraging more use of imaging systems).
From: owner-wims at pwg.org [mailto:owner-wims at pwg.org] On Behalf Of
Richard_Landau at Dell.com
Sent: Thursday, May 15, 2008 1:55 PM
To: nchen at okidata.com
Cc: wims at pwg.org
Subject: WIMS> RE: CIM object requirement for WS-Management
Nancy, I'm sorry that I wasn't clearer about the structure and future of web
service management in the printer space. Thank you for the question.
Clarification follows, I hope. I think this deserves a real answer, not
just yes-no. And I think a lot of people need to hear the answer. I hope
you don't mind my sending this reply to a broader audience.
- WS-Management is not restricted to transferring CIM-based objects. The
WS-Man protocol can be used with any sort of objects. In this sense, it is
like SNMP without MIBs. WS-Man includes Get, Put, Enumerate (and so forth)
just as SNMP includes Get, Set, GetNext (and so forth).
- A protocol is not sufficient to manage a device. You still have to define
the management data objects that are to be manipulated by the protocol
operations. For SNMP, one defines MIBs, lots of them, to specify the syntax
and semantics of the data to be manipulated. For WS-Man, the only public,
standard definitions so far are CIM objects.
- DMTF (dmtf.org) publishes the WS-Man protocol standard as its document
DSP0226. It also publishes the WS-Man CIM Binding spec, which describes how
CIM objects are to be named and manipulated using WS-Man, as DSP0227. And
the XML representation of CIM objects for use by web services is described
in DSP0230. The entire CIM schema is also published by DMTF and updated
three times per year.
- PWG has just invested considerable effort in defining the CIM classes for
a Printer device to match the model of the Printer MIB and the Semantic
Model. The CIM schema v2.19 now contains about fifteen classes and a
hundred properties that very closely parallel the Printer MIB. So,
theoretically, it would now be possible to manage a printer using a modern
web service, WS-Management.
- As a proof of the mapping from SNMP to CIM schema, I am building a
prototype of a proxy provider for a CIM server. This will take SNMP data
from a network printer and re-publish it in a CIM Object Manager ("CIMOM,"
such as WMI on Windows) using these new printer-related classes.
- If someone wants to invent another mapping of the industry-standard
printer management data to some other data model, he/she is free to do that.
However, the result won't be any smaller or simpler than the one that was in
the Printer MIB -- and is now in the CIM schema. Sure, it's possible, but
why bother? We already invested the man-year or two necessary to define
that data in a published standard. Any sensible implementer will simply use
what is available.
- Many of us are convinced that web services will become popular management
protocols, and over time will become the dominant protocols. If something
is not manageable by a web service protocol, at some point in the future, on
some set of corporate networks, it simply won't be manageable at all.
- Overhead? Sure, everything has overhead. The SNMP agent in a printer has
overhead, and manufacturers complained about that expense when it was first
implemented. The HTTP web service in a printer has overhead, and
manufacturers complained when it was first implemented. So, too, the WS-Man
service management agent in a future printer will have overhead, and we will
complain about that. But if we want a device to be manageable in corporate
and educational networks, we have no choice. Customers insist on
out-of-band management as a feature of all network devices.
- I will point out that, as of late this year, every new business desktop
and laptop computer system will have a complete, WS-Man-based, out-of-band,
management agent, using (dozens of) CIM classes to transfer data. Look for
"DASH" in the feature list. The major vendors will be using chips developed
by a number of companies, including all the major NIC and management
controller companies, in any new system that requires remote management.
The overhead for this agent is small, and largely in silicon.
So, to answer your question, No, WS-Management is not *required* to use CIM
objects, but it *can* use CIM objects. And CIM objects represent a very
rich and growing set of management objects for computer systems and
peripherals. If one wants to include web service management in a device,
the WS-Management and CIM schema standards are already available.
Richard_Landau(at)dell(dot)com, Stds & System Mgt Architecture, CTO Office
+1-512-728-9023, One Dell Way, RR5-3, MS RR5-09, Round Rock, TX 78682
From: nchen at okidata.com [mailto:nchen at okidata.com]
Sent: Thursday, May 15, 2008 09:49
To: Landau, Richard
Subject: CIM object requirement for WS-Management
I remember at the beginning of WIMS-CIM alignment project, you mentioned
that in the future WS-Managet will only accept CIM objects.
Is this still true? I don't see this compliance statement in WS-Management
spec, neither the claim at DMTF CIM web site. Would you please verify this
remains true? If so, do a device wishing to be managed by WS-Management need
to embedded their management data in CIM objects within the device? I see a
lot of overhead in this.
Solutions and Technology
2000 Biships Gate Blvd.
Mt. Laurel, NJ 08054
Phone: (856) 222-7006
Emal: nchen at okidata.com
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