[avahi] Re: [avahi-commits] r637 - /trunk/service-type-database/service-types

[Trent Lloyd]

On Thu, Sep 29, 2005 at 07:15:43PM +0200, Lennart Poettering wrote:
> On Tue, 27.09.05 22:07, Marc Krochmal (marc at apple.com) wrote:
> 
> > >>I'm also wondering what you mean by the comment that says dns-sd.org
> > >>"is not a source that complies with the criterion".  The list on dns-
> > >>sd.org doesn't really have a license because it's just a list of
> > >>service types.  If you feel like you can't use this list, then I'm
> > >>sure we'd be willing to slap a BSD style license header to the top of
> > >>this page.
> > >
> > >Yes, A BSD license would be nice for that. Does the list exist in a
> > >form that is more easily parsed for generating a gdbm file?
> > 
> > Yeah, we've had requests for this.  Just haven't gotten around to it  
> > yet.
> 
> Do I have your informal assurance that it is OK if we integrate that
> database into our software under a BSDish license right now? (no APSL
> please!)
> 
> > >>I think RSS is important enough that we should think about this a
> > >>little first, because whatever we decide, it will be in use for many
> > >>years, and it's always a pain if applications that used to browse for
> > >>the *wrong* type then have to transition to the new type by browsing
> > >>for both for a little while.  I hate it when that happens.  :-)
> > >
> > >Hmm, HTTP 1.0/1.1 are completely upwards and downwards compatible as
> > >far as I know. However this is not true for RSS 0.91 vs. RSS
> > >2.0. That's why I used different service types for them.
> > 
> > I pretty much know nothing about RSS, but according to this site.
> > 
> > <http://blogs.law.harvard.edu/tech/rss>
> > 
> > "The elements defined in this document are not themselves members of  
> > a namespace, so that RSS 2.0 can remain compatible with previous  
> > versions in the following sense -- a version 0.91 or 0.92 file is  
> > also a valid 2.0 file. If the elements of RSS 2.0 were in a  
> > namespace, this constraint would break, a version 0.9x file would not  
> > be a valid 2.0 file. "
> > 
> > So it sounds like a client that understands RSS 2.0 feeds will also  
> > understand RSS 0.9.x feeds.  This means that older RSS clients  
> > browsing for "_rss" might discover newer 2.0 feeds that they wouldn't  
> > be able to parse.  I'll bet that if a customer came across a feed  
> > that they couldn't read, they would quickly replace their out-dated  
> > RSS client with a newer version, so this problem solves itself.
> 
> Not quite. RSS2.0 doesn't pass validation with a RSS0.91 DTD. (And I
> guess the other way around it is true too). Some RSS parsers do a DTD
> validity check before processing the RSS data. (ideally all should)

It's worth nothing that most applications publish both an RSS0.91 and
2.0 feed, so some separation may be worthy.

However, applications should adapt to the feed type and using more than
1 type means we will have to keep changing the publish services down the
line, and maybe in 10 years we will have 8 different rss services being
published. :)

Trent

> > Actually, it's "sftp-ssh".  The only reason we did that was because  
> > the IANA protocol list already had an "sftp", Simple File Transfer  
> > Protocol, so we had to pick something else.
> > 
> > <http://www.iana.org/assignments/port-numbers>
> > 
> > We decided on "SFTP over SSH", or "sftp-ssh".  Similar sounding to  
> > "TCP over IP" or "TCP/IP".  I guess since RSS could use a different  
> > transport protocol, then it might make sense to call it "RSS over  
> > HTTP", "rss-http".
> 
> Ok, I guess I could live with that.
> 
> > >BTW: May I politely ask you to add a link to Avahi on either
> > >dns-sd.org or multicastdns.org, the way you already added a link to
> > >those Java, Ruby or Python implementations?
> > 
> > No problem.  I added a link for you.
> 
> Thank you very much.
> 
> Lennart
> 
> -- 
> Lennart Poettering; lennart [at] poettering [dot] de
> ICQ# 11060553; GPG 0x1A015CC4; http://0pointer.de/lennart/
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-- 
Trent Lloyd <lathiat at bur.st>
Bur.st Networking Inc.