Subject: Re: [lisp] Can I get opinions?

From: [email-masked] (Noel Chiappa)
Date: Thu, 28 May 2009 16:45:45 -0400 (EDT)

> From: Damien Saucez <[email-masked]>

    > As we are talking about changing the header, it would be the perfect
    > time to discuss versioning again, isn't it?

On this particular point, I don't see that anything has changed from my prior
analysis to Margaret - we have a number of ways to make a change (if the need
for one arises), and to try and chose one now would be to make a choice with
limited data.

    > discuss on the mailing list what we would really see in the headers.

This I can see. Did you have any particular thoughts/suggestions? (I have one
from Olivier in my overflowing emailbox, which I have yet to respond to... :-)

    > I think that functionalities in the protocol are more important than
    > implementation issues.

On this we sort of agree, because this whole 'make changes' issue is
something I have been musing about recently. Here are a few things I said to
the LISP authors recently:

 Right now we're in a place where we can do 'flag days' - just change stuff
 around. Once we have an installed base, we can't do that any more, we have
 to go the 'interoperable' route. However, more protocols have died through
 freezing too soon than just about anything else. (Tuba, etc, etc.)

 Look at the early history of IP - the incompatible changes from 'IP'v2 to
 IPv2.5 to IPv3 were very significant - and that effort was dealing with a
 _lot_ more installed test base, and many more implementations and
 implementors. It was that willingness to keep changing things _for a long
 time into the early life of the protocol_ that is a large part of IPv4's
 success.

So I am very much in sympathy with your basic thought.

However...

LISP has been around for a couple of years now, and people out in the world
are starting to wake up to it. The ability to add an additional binding layer
is something that a lot of people are very interested in. What that means is
that there is now an open 'window of opportunity' to get LISP actually
deployed and into significant use, and in my opinion we should _not_ take a
chance on throwing away that window, by tinkering for an extended period of
time.

    > I hope we will not limit the changes in the protocol just because of
    > "legacy" code.

As far as I know, right at the moment there is no significant 'legacy code
base' to worry about. The list of implementations (that I know of) is fairly
short.

	Noel