Re: [forces] draft-ietf-forces-model-extension

Greetings Julian,

I'm a little confused on why you think there is no backwards compatibility.

LFB definitions that use the 1.0 namespace are valid in the 1.1 namespace.
LFB definitions that use the 1.1 namespace are not always valid with the 1.0
namespace.

That means that a software that understands LFBs in the 1.1 namespace can,
without any change, understand older LFBs. That was the end goal.
Software that understand the 1.0 namespace (even if we didn't change the
namespace) will, of course, have trouble parsing the new xml if the
extensions are used.

This document did not change any LFB definitions developed with the 1.0
namespace. As there was no reason for that as 1.1 is backwards compatible
with 1.0
The namespace is a way to distinguish the different versions and notify that
in the 1.1 namespace these extensions apply.

Thus, I don't understand why old software will be needed to change in order
to understand the old format. 
For the new format, of course you'll have to change it. But for the new
format you'd definitely had to update the software if you want to be
compatible with the 1.1 namespace, so I don't see the issue.

Is something I miss?

Regards,
Evangelos Haleplidis.

> -----Original Message-----
> From: forces [mailto:forces-bounces@ietf.org] On Behalf Of Julian
> Reschke
> Sent: Wednesday, October 22, 2014 10:33 AM
> To: draft-ietf-forces-model-extension@tools.ietf.org; forces@ietf.org
> Cc: Amanda Baber; Graham Klyne
> Subject: Re: [forces] draft-ietf-forces-model-extension
> 
> On 2014-10-22 09:06, Julian Reschke wrote:
> > Hi there.
> >
> > I was reviewing the namespace registration and have one question.
> >
> > The draft says
> >
> > "The changes introduced in this memo do not alter the protocol and
> > retain backward compatibility with older LFB models."
> >
> > If this is the case, why is a new XML namespace even desirable?
> >
> > (Other than that, I'm sort of ok with the registration, but it
> strikes
> > me that assigning a new namespace is a very bad idea).
> >
> > Best regards, Julian
> 
> Thinking about that some more: if a new XML namespace is used, the
> format definitively is *not* backwards compatible anymore (every piece
> of software that understood the old format will have to be rewritten).
> 
> Best regards, Julian
> 
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