IPP> SLP - Summary of next 'printer:' template proposal

IPP> SLP - Summary of next 'printer:' template proposal

IPP> SLP - Summary of next 'printer:' template proposal

Ira McDonald imcdonal at sdsp.mc.xerox.com
Wed Jan 13 20:45:16 EST 1999

Hi folks,                                    Wednesday (13 January 1999)

This note seeks concensus before a next revision of the SLPv2 'printer:'
template.  PLEASE send your opinion to the IPP mailing list.  Also, the
SLPv2 'printer:' template will be discussed at the PWG monthly meeting
next week in Maui, Hawaii - but I won't be there - sigh...

Our concensus at today's IPP WG Telecon was:
a)  Use the SLPv2 'printer:' template as the master for writing coherent
    SLPv1-compatible concrete templates for each print protocol;
b)  REDUCE attributes in the SLPv2 'printer:' template from mandatory to
    optional, whenever reasonable;
c)  Let the IPP Model raise the conformance level for certain optional
    attributes (but only for IPP supporting printers);
d)  Specify a default value of 'unknown' or '-1' (STRING or INTEGER)
    for each optional attribute (so that an SLP User Agent can tell if
    the registration includes meaningful information, even in SLPv1);
d)  DELETE 'print-quality-supported' from the SLPv2 'printer:' template,
    because it is too subjective to be useful (unlike nominal speed);
e)  ADD a new second printer speed attribute 'pages-per-minute-color'
    (also to be added to IPP/1.0 as a registered extension).

Per my action item from today's IPP WG Telecon, here is a summary of all
attributes planned for a next revision of the SLPv2 'printer:' template,
with their SLP syntax (and flags), SLP status (mandatory or optional),
and IPP status for directory registrations (NOT for IPP Printer objects)
- per Appendix E 'Generic Directory Schema' of IPP Model and Semantics
(16 November 1998).

The next SLPv2 'printer:' template (summarized here) would have (28)
attributes, including (6) mandatory ones and (22) optional ones.  After
the summary table, a rationale is presented for EACH mandatory or
optional attribute.
- Ira McDonald (outside consultant at Xerox)
  High North Inc
  716-461-5667 (w/ voice mail)

PS - Harry Lewis posted my last update to the SLPv2 'printer:' template
today in the directory 'ftp://ftp.pwg.org/pub/pwg/ipp/new_SLP'.  Sorry I
failed to post this revised template before, except on the mailing list.


SLP Flags
L    Literal (NOT to be translated)
M    Multi-valued (comma separated in template)
O    Optional (not mandatory in template)

SLPv2 'printer:' Attribute         SLP Syntax    SLP Status  IPP Status
Name (usually IPP Name)            and Flags     (Directory) (Directory)
--------------------------         ----------    ----------- -----------
printer-uri-supported <1>          STRING L      Mandatory   Recommended
uri-security-supported <2>         STRING L      Mandatory   Recommended
printer-name <3>                   STRING        Mandatory   Recommended
printer-location (1)               STRING O      Optional    Recommended
printer-info (2)                   STRING O      Optional    Optional
printer-more-info (2)              STRING L O    Optional    Optional
printer-make-and-model (2)         STRING O      Optional    Recommended
printer-current-operator (1)       STRING O      Optional    (PrintMIB)
printer-service-person (1)         STRING O      Optional    (PrintMIB)
natural-language-configured <4>    STRING L      Mandatory   (no status)
natural-language-supported <5>     STRING L M    Mandatory   Optional
charset-configured (3)             STRING L O    Optional    (no status)
charset-supported (3)              STRING L M O  Optional    Optional
document-format-supported <6>      STRING L M    Mandatory   Recommended
color-supported (2)                STRING L O    Optional    Recommended
finishings-supported (2)           STRING L M O  Optional    Optional
number-up-supported (2)            INTEGER M O   Optional    Optional
sides-supported (2)                STRING L M O  Optional    Recommended
media-supported (2)                STRING L M O  Optional    Recommended
media-local-supported (2)          STRING M O    Optional    (see above)
printer-resolution-supported (2)   STRING L M O  Optional    Optional
[print-quality-supported] (4)      STRING L M O  Optional    Optional
copies-supported (2)               INTEGER O     Optional    (no status)
job-k-octets-supported (2)         INTEGER O     Optional    (no status)
pages-per-minute (2)               INTEGER O     Optional    (new in IPP
pages-per-minute-color (2)         INTEGER O     Optional    (new in IPP
delivery-orientation-supported (2) STRING L O    Optional    (PrintMIB)
priority-levels-supported (2)      INTEGER O     Optional    (Salutation
paper-output (2)                   STRING L M O  Optional    (Salutation

Mandatory attribute rationales
<1> printer-uri-supported       supports single registration object
                                - all print protocol paths (per IPP/1.0)

<2> uri-security-supported      supports direct use of each printer URI
                                - required security (per RFC 2316)

<3> printer-name                supports user-friendly access to printer
                                - natural language name (per IPP/1.0)

<4> natural-language-configured supports direct use of each printer URI
                                - configured language (per RFC 2277)

<5> natural-language-supported  supports direct use of each printer URI
                                - supported languages (per RFC 2277)

<6> document-format-supported   supports direct use of each printer URI
                                - supported PDLs (per IPP/1.0)

Optional attribute rationales
(1) Often not configured by system administrators (per Hugo Parra)
(2) Often unknown to print servers (per Hugo Parra)
(3) ALL Internet application protocols MUST support UTF-8 (per RFC 2277)
(4) Propose to DELETE in next SLPv2 'printer:' template (per Hugo Parra)

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