Re: New draft on Extra class LSP

["Adrian Farrel" <adrian@olddog.co.uk>]

Vishal,

> I'm sorry, but I'm still not clear on the meaning of "extra traffic."
> Perhaps I need to go back and look again at it, and think about it
> a bit.

> As an alternative, perhaps some other folks on the list who are clear
> on these definitions could take a stab at helping those of us who are
still
> unclear understand them.

My attempt...

I think there is a subtle difference between ordinary pre-emption and extra
traffic.
That is, when resources are pre-empted in the ordinary way and then the
pre-empting LSP is torn down, the resources are freed up and completely
unused.
When resources for a secondary LSP are used for extra traffic and then the
extra traffic LSP is torn down, the resources revert to their "reserved for
the secondary LSP" state. This means that those resources are only available
for
- full pre-emption
- extra traffic use
They are not made available for general use.

> (And, I'd certainly like to find out from the list,
> if I'm the only one confused here, and, if so, see if people can point
> me in the right direction.)

I think this is a reasonable subject for confusion! It gets talked about as
a concept far more than it get deployed as a workable option.

Perhaps a couple of detailed paragraphs should be added to one of the
protection drafts.

Adrian