IPP> SLP 'printer:' template comments

IPP> SLP 'printer:' template comments

IPP> SLP 'printer:' template comments

Ira McDonald imcdonal at sdsp.mc.xerox.com
Sun Jan 10 13:17:53 EST 1999


Hi Hugo,                                        Sunday (10 January 1999)

My replies are imbedded in your note below.  Thanks for your thoughtful
review of this draft 'printer:' template.

I would also like your opinion.  Should we have two separate printer
speed attributes (one for nominal black-and-white and one for nominal
color speed)?

Tom Hastings has also asked whether SLPv1 supports 'presence' filters on
attributes.  The answer is no.  Both SLPv1 and SLPv2 do have support for
default values on optional attributes.  I suggest that we demote as many
mandatory attributes to optional as possible, then give them all default
values of 'unknown' (string or enum) or '-1' (integer).

Cheers,
- Ira McDonald (outside consultant at Xerox)
  High North Inc
  716-461-5667

>-----------------------------------------------------------------------
> To: <ipp at pwg.org>, <srvloc at srvloc.org>
> Cc: "Hugo Parra" <HPARRA at novell.com>,
>     "Dale Bethers" <DBETHERS.PRV-MAIL1.PROVO at novell.com>,
>     "Mark Killgore" <MKILLGORE.PRV-MAIL1.PROVO at novell.com>
> Subject: IPP> SLP 'printer:' template comments
> 
> I'd like to propose the following changes to the SLP 'printer:' template
> spec recently distributed by Ira.
> 
> 1. The template-url-syntax needs to include definitions for NDPS and TCP
> printers.  The NDPS flavor would look as follows,
>     ndpsurl = "ndps://" hostport [ nds-name / pa-name ]
>     nds-name = "/nds/" fqn
>     fqn = /* fully qualified NDS printer name */
>     pa-name = "/pa/" printer-name
>     printer-name = /* NDPS printer agent name */

Agree.  We should add this NDPS URL and we should also add Port 9100 for
raw TCP printing.  What about adding PServer URLs for NetWare SPX/IPX
protocol environments (see below)?

Probably a dumb question, but does NDPS only run over Internet TCP/IP or
does it also run over SPX/IPX?  As you are probably aware, SLPv2 permits
both NetWare and AppleTalk addresses to be specified in registered SLP
'service:' URLs.  So we might want an 'ndpsipxurl' syntax as well?

> 2. uri-security-supported, add 'nds-sec' to legal values.

Could you state a document name for 'nds-sec' for the References section
of the 'printer:' template?  Would 'nds-sec' add extra parameter(s) to
an 'ndps:' URL?

> 3. printer-location, make it optional.  Very few administrators set this
>    up today and it's optional in IPP.

Agree.  And make the default value "unknown".

> 4. printer-current-operator, make it multi-valued.  PServer and NDPS
>    support multiple operators.

Agree.  And make the default value "unknown".
Should we change this attribute name to plural?

> 5. printer-service-person, make it multi-valued.

Agree.  And make the default value "unknown".
Should we change this attribute name to plural?

> 6. natural-language-configured, add 'client-dependent' to legal values.
>    NDPS returns error and status info in the form of OIDs.  Clients
>    translate those OIDs to localized strings.

Disagree.  The registered value of 'natural-language-configured' states
the actual language of 'printer-description' and other attributes is NOT
merely information about the print service.  In addition, the syntax of
'natural-language-configured' in IPP/1.0 is an RFC 1766 'language tag',
where 'client-dependent' would be an illegal value.

> 7. natural-language-supported, add 'client-dependent' to legal values.

Disagree.  See above.

> 8. document-format-supported, make it optional.  It's not always
>    available to print servers front-ending legacy printers.

Agree.  And make the default value "unknown".

> 9. color-supported, add 'unknown' as legal value.

Agree.  And make optional with default value "unknown".

> 10. sides-supported, consider making optional.

Agree.  And make the default value "unknown".

> 11. media-supported, make optional.

Agree.  And make the default value "unknown".

> 12. media-local-supported, make optional.

Agree.  And make the default value "unknown".

> 13. print-quality-supported, consider removing.  Print quality is so
>     printer-specific that I question the benefit of having it as an SLP
>     search criteria.

Agree.  This attribute is much fuzzier than nominal printer speed.

> 14. copies-supported, rename to max-copies-supported.  For
>     clarification.

Agree.  And make default value "-1" mean unknown, not unlimited.

> 15. job-k-octets-supported, rename to max-job-k-octets-supported.

Agree.  And make default value "-1" mean unknown, not unlimited.

> 16. printer-mechanism-types, consider adding.

As Tom already asked, what are the details of this attribute?  Is this
printer technologies (e.g., inkjet versus laser)?
If so, both versions of the Printer MIB have the mandatory attribute
'prtMarkerMarkTech' with a rich list of marking technologies.

> 
> This is my first shot a this.  If there are strong reasons for doing
> things differently, let's hear them.
> 
> -Hugo
> 

Thanks for this excellent first shot.  If other folks could comment on
this template so thoroughly, it would be a big help - Ira
>-----------------------------------------------------------------------




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