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

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

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

Ira McDonald (imcdonal@sdsp.mc.xerox.com)
Wed, 13 Jan 99 20:45:16 EST

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)