RE: IETF54- Informal discussion on BC Model for DS-TE

["Geib, Ruediger" <Ruediger.Geib@t-systems.com>]

Hi Jerry

> > Russian Dolls model does not "mandate" the use of 
> > preemption. It just uses it for what it has been specified 
> > for (ie bounce off LSPs when needed).
> > 
> > My impression is that it is just not possible to simultanesouly :
> >          -(i) ensure bandwidth sharing (ie no bandwidth wastage)
> >          -(ii) ensure bandwidth isolation (ie a CT cannot 
> >               have some of its bandwidth taken by another CT)
> >          -(iii) refuse to use preemption
> > 
> > I believe SPs have requirements for (i) and (ii) and don't 
> > have a problem with using preemption, which is an existing
> > TE mechanism.
 
> Not all SPs assume the use of preemption.  So the default BC 
> model should not assume ('require') the use of preemption to 
> operate efficiently.

Yes, that's correct. I'd prefer a default BC model where 
preemption is an optional add on instead of a mandatory feature.

Regards, Rüdiger