Re: WG last call: draft-ietf-tewg-diff-te-reqts-04.txt

[Indra Widjaja <iwidjaja@research.bell-labs.com>]

Sudhakar Ganti wrote:
> 
> Jim,
> 
> Unless the document defines what exactly is a "consistent
> behavior" across multiple implementations and discusses
> what are the implications of not having a default model,
> the requirements document should not mandate that a default
> model (whatever that is) must be supported by any DS-TE
> implementation.

I'd like to echo Sudhakar's concern in that the whole picture
of BC models seems not fully understood yet.
Wouldn't it be possible to have multiple BC models in a domain
and let an LSR optimize its individual LSP depending on whether
bandwidth sharing or isolation is more important? Would this 
so-called "inconsistency" have adverse effect on the network
efficiency or some other factors?

indra

> 
> -Sudhakar
> 
> > > The DS-TE technical solution must specify one
> > > default bandwidth constraint model which must be supported by any
> > > DS-TE implementation.  Having a default bandwidth constraint model
> > > allows for the network administrator to have at least one
> > consistent
> > > behavior when working with multiple implementations of DS-TE.
> > > Additional bandwidth constraint models may also be
> > specified. In the
> > > selection of a default model, at least the following
> > criteria must be
> > > considered:
> > > (1) addresses the scenarios in Section 2
> > > (2) works well under both normal and overload conditions
> > > (3) applies equally when preemption is either enabled or disabled
> > > (4) minimizes signaling load processing requirements