Date: Tue Feb 14 2006 - 22:32:32 EST
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" <firstname.lastname@example.org>
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.
-- Paul Tykodi Principal Consultant TCS - Tykodi Consulting Services LLC
From: email@example.com [mailto:firstname.lastname@example.org] On Behalf Of Bergman, Ron Sent: Tuesday, February 14, 2006 7:02 PM To: email@example.com 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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