Re: Flow label versus Extension header - protocol itself

[Erik Nordmark <erik.nordmark@sun.com>]

Greg Daley wrote:

> > I don't think it makes sense switching from F1 to a different locator 
> > for the "main" path as you parenthetically suggest, though.
>
>
> Fair enough.  The main value of retaining the flow label F1 though,
> is for applications which are interested in flow identification.

By "applications" do you mean something running on the host?

My assumption is that the shim on the receiver would not only restore 
the IPv6 address fields to be the ULIDs, but also restore the flow label 
to F1. Thus ULPs on the host would see a constant flow label.

> The main thing I guess is that it doesn't break any existing flows while
> the flow remains on the original path.

Yep.
And when switching to a different locator pair, and some flow signaling 
is used, one would need to do the flow signaling for that locator pair 
in any case. So using a different flow label for the different locator 
pair shouldn't be much of an issue.

   Erik