Hi, Saturday (21 August 2010)
Per my action item from our August 2010 PWG Meeting, here is my proposal
for a new IPP spec called "IPP Printer Device Extensions".
Since the complete ABNF and mapping rules for all 170+ objects defined
in the Printer MIB will be fairly long, I suggest that this should be in
a separate IPP spec and not simply included in "IPP Everywhere" spec.
Comments?
Cheers,
- Ira
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Approach:
- Avoid use of new Object (e.g., Device) or Collection to reduce cost
for lightweight mobile implementations of IPP Clients
- Follow style of IPP PSX mapping of prtAlertTable, i.e., array of text
parameters in "printer-alert" representing most columns and separate
attributes like "printer-alert-description" for string MIB objects
- Convert all enumerated values from Printer MIB into IANA registered
string names, e.g., "prtChannelType" of "38" maps to "chBidirPortTCP"
- Map bit masks, e.g., "prtChannelStatus (PrtSubUnitStatusTC), directly
as integers (because string encoding in IPP is too verbose)
Pros:
- Simple human-readable text encoding
- Lightweight (no new attribute groups, objects, etc.)
- High fidelity mapping from Printer MIB objects to IPP attributes
Cons:
- Like "printer-alert", maps a *single* physical output device onto an
IPP Printer object
- Note that this precedent was already established with "printer-alert"
which has shipped in CUPS and various printers for several years
Examples:
printer-channel[1] =
"index=1;type=chBidirPortTCP;jclIndex=0;pdlIndex=1;
state=printDataAccepted;ifIndex=3;status=0;"
printer-channel-version[1] =
"Bi-Directional Raw TCP/IP Printing"
printer-channel-info[1] =
"Port=9100"
printer-marker[1] =
"index=1;markTech=inkjetAqueous;counterUnit=impressions;
lifeCount=23412;powerOnCount=479;processColorants=4;
spotColorants=0;addressUnit=tenThousandthsOfInches;
addressFeedDir=600;addressXFeedDir=600;
northMargin=1066;southMargin=1066;eastMargin=1066;westMargin=1066;
status=0;"
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