Subject: Re: [IPP] Minutes posted from today's concall

From: Soma Meiyappan <[email-masked]>
Date: Mon, 4 Aug 2014 06:17:39 +0000

Hi Mike/Pete et al,

Thank you very much for the notes, Mike.

On "[IPP Scan LastCall comments] TC 4: Defer until Pete and Soma can provide background; possible Note: in text": If we have a USB only IPP Scan device (for that matter, a printer device too) that does not have an RTC chip/battery that maintains clock out-of-factory (and certainly does not have network support to use NTP), it does not have a well-defined way to get/set current time. All relevant IPP standards make some form of date-time mandatory. However, a device, described above, is typically not capable of providing accurate date-time. They may provide their notion of time (which may be based on heuristics incl born-on date or simply UNIX epoch); but the accuracy of the reported date-time is unspecified. A device that supports WiFi P2P only & no RTC is in a similar position. 

I believe that some guidelines to reconcile the requirement of date-time and how these devices may handle the requirement will clarify implementation options for client/server developers. This could take any of the following (or anything else suitable):
1. date-time-xxx and related attributes are conditionally required for devices with network interfaces incl devices with only P2P network connections (USB devices do not have to support these attributes)
2. date-time-xxx and related attributes is required for all IPP devices. Devices that do not have a way to maintain accurate date-time in the device across power-cycles may make their notion of wall clock time available obtained through any network services like NTP/SNTP (best effort), user set value or a value derived (i..e, counted up suitably on a timer) from a value that is arbitrarily assigned at every power-up.
3. The accuracy of the date-time-xxx and related attributes that are mandatory should conform to the specifications mentioned in section xxxxx of PWG xxxx.yy/RFC xxxx.

The notes describing PWG's position on these attributes will determine if RTC (and a way for the user to change the date-time) is required for all devices. Of course, this may mean additional cost to OEMs.

Thanks and Regards,
Somasundaram.

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Michael Sweet
Sent: Tuesday, July 29, 2014 4:53 AM
To: <[email-masked]>
Subject: [IPP] Minutes posted from today's concall

All,

I have posted the minutes from today's IPP WG conference call to:

	http://ftp.pwg.org/pub/pwg/ipp/minutes/ippv2-concall-minutes-20140728.pdf

Our next conference call is on August 4, 2014 at 3pm with the Cloud Imaging Model WG to review slides for the F2F.

_________________________________________________________
Michael Sweet, Senior Printing System Engineer, PWG Chair

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