Subject: Re: Relationship DNS-SD and SLP

From: Stuart Cheshire <[email-masked]>
Date: Tue, 30 Jul 2002 21:16:26 -0700

>A client can request a printer with a SLP service request including
>
>  service type =  service:printer:ipp
>         scope =  default
>         query =  (printer-media-supported=iso-a4)
>
>It will receive a SLP service reply with:
>
>  service URL =  service:printer:ipp://169.254.23.16:631/myqueue

At the risk of repeating myself, one of Apple's requirements is 
user-friendly names. (But I don't think this requirement is unique to 
Apple.)

"ipp://169.254.23.16:631/myqueue" is not a user-friendly name.

User-friendly names SHOULD allow any characters the user desires (e.g. 
upper case, lower case, spaces, punctuation, non-roman characters, etc.)

User-friendly names SHOULD NOT require a name to contain cruft the user 
does not desire (e.g. "ipp://169.254.23.16:631" or similar). Such cruft 
may be part of the protocol on the wire, but should not be a necessary 
part of the UI.

Stuart Cheshire <[email-masked]>
 * Wizard Without Portfolio, Apple Computer
 * Chairman, IETF ZEROCONF
 * www.stuartcheshire.org

---

From: Keith Moore <[email-masked]>
Date: Wed, 31 Jul 2002 01:41:01 -0400

> "ipp://169.254.23.16:631/myqueue" is not a user-friendly name.

Indeed.  But people shouldn't have to see such things unless they want to,
or unless they specifically need to select based on IP address, port,
etc.  (sometimes they do, but it should be rare for small-scale setups).

Does something prevent SLP from returning one or more user-friendly names
along with the URL?
 
> upper case, lower case, spaces, punctuation, non-roman characters, etc.)

well, maybe.  One can argue that allowing arbitrary content in a name
actually makes them less user-friendly by making it more difficult to 
type the name in correctly.  User-friendly doesn't necessarily imply
point-and-drool.
 
Keith

---

From: Erik Guttman <[email-masked]>
Date: Wed, 31 Jul 2002 11:12:53 +0200 (CEST)

> Does something prevent SLP from returning one or more user-friendly names

SLP allows a user friendly name attribute, even a (binary) colorful icon
attribute. This is what would appear in human interfaces.   The URI is
only used by applications.

Erik

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From: "John C. Welch" <[email-masked]>
Date: Wed, 31 Jul 2002 11:33:48 -0400

> type the name in correctly.  User-friendly doesn't necessarily imply

No, but humans like arbitrary content. As well, if you work with people that
don't read english that well, being able to set up printer queues in their
native language isn't a convenience, it's a necessity. Simple is good, but
quite hard to do right. But that's what users want. Along with the ability
to assign some rather silly names to things...like B0bz pr1nt3r

john

-- 
John C. Welch
IT Manager
MIT Police
(617) 253 - 3093 work
(508) 579 - 7380 cell
(617) 253 - 8822 fax

---

From: "John C. Welch" <[email-masked]>
Date: Wed, 31 Jul 2002 11:34:11 -0400

> only used by applications.

That's all well and good, but I have yet to see anyone implementing SLP in a
usable fashion for things like printing. It's certainly not being
implemented at home, or in the small business. I've thought about using SLP
as a replacement for AppleTalk zones, but, have found that while the idea
may certainly be full-featured and elegant, the implementation, to put it
bluntly, blows.

I have a rather nice Xerox Phaser 1235DX, supports almost ever protocol you
would want to print with. But to use SLP with it, you have to do that at the
server, because the printer doesn't support it. So I have to set up SLP just
to allow non-Appletalk print browsing. That's a pain, even in a small
situation. Now, multiply that across a really large domain.

john

-- 
John C. Welch
IT Manager
MIT Police
(617) 253 - 3093 work
(508) 579 - 7380 cell
(617) 253 - 8822 fax