The MPLS WG Archive

[Grenville Armitage <gja@dnrc.bell-labs.com>]

Francois,

I'm gradually getting time to continue our discussion of
my other points. In this email, my suggestion #9:

Francois Le Faucheur wrote:
	[..]
> >#9 Preconfigured E-LSP EXP<->PHB mapping?
> >
> >   Section 3.2.1 talks about a preconfigured EXP<->PHB mapping
> >   but does not suggest a default. I think the document ought to
> >   specify an actual default for EXP 000 to map to Best Effort PHB
> >   (or set of defaults where *all* EXP values map to BE).
> >
> 
> The Network Adminsitrator is expected to configure the
> "preconfigured EXP<->PHB mapping" depending on the BAs that
> are actually used in his/her network. Since differenet Network
> Administrators are likely to run differnet subsets of BAs it is
> difficult to define a Default mapping that would be generally
> useful.

Agreed, generally useful non-BE mappings would be hard to
get WG agreement on.

> But I guess you are saying , it would be useful to have
> a default mapping in case the preconfigured mapping hasn't been
> configured at all by the Network Adminsitrator. Right?

Yes. I contemplated suggesting a set of eight BAs, but
didn't want to open up a can of worms regarding which
eight BAs are important enough to mandate that an LSR
support. So....

> In that case, I suppose I woudl also map all EXP values
> towards BE.

Yes, I think it would be beneficial for the text to at least
nominate the default behavior for every EXP value (or at least
EXP=000) to be Best Effort. Although such a default is kind
of intuitive, its worth stating. The text can easily reassure
readers that local configuration is always entitled to override
the default.

cheers,
gja
________________________________________________________________________
Grenville Armitage                    http://members.home.net/garmitage/
Bell Labs Research Silicon Valley