>
> 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 respectfully disagree. I believe that (i) and (ii) can be achieved
simultaneously with (iii). Preemption of LSPs at a lower service level
in order to allow LSP calls at a higher service level is not the only
way to achieve (i) and (ii). An alternative would be to allow a
potential service degradation of the already established LSPs at a lower
service level without totally removing (often in an arbitrary way) any
particular LSP from the service. Given my example, the sum of normalized
CT1 and CT0 reservations would be allowed to exceed BC0.
Let's see if I understand exactly what you are proposing. If I understand
correctly, you're arguing in favor of the Max Allocation model where you
would configure the sum of the constraints much larger than the total capacity.