The MPLS WG Archive

[David Charlap <David.Charlap@marconi.com>]

Markus Jork wrote:
> 
> The latest iterations of the RSVP-TE spec suggest that a CoS object
> or the Null service be used to signal best-effort.

What version are you reading?  The CoS FLOWSPEC/TSPEC were explicitly
deleted from the draft as of version -08.  I haven't heard any mention
any anybody putting it back.

> I don't think anybody sends a CoS object by default when requesting
> best-effort.

There are some.

> That would cause interoperabilty problems. I'm not sure about the
> support for the Null service in current implementations.

So far, it appears that Null service is not widely supported.  CoS seems
to be supported by most, but not all, platforms.

> The changes in the RSVP-TE spec dealing with best-effort signaling
> (first the introduction of the CoS object and then it's replacement
> with the Null service) were rather unfortunate. It really was just
> a change in syntax, not any technical improvement. The good thing
> is that the Null service promoted in the latest spec looks like
> the aesthetically most pleasant solution, the bad thing is that these
> syntax changes are just a waste of time for everybody involved and
> an interoperability hazard.

I know.  And it may be years after the spec becomes an RFC before all
the major players decide to upgrade their code to support Null service.

Which is why I asked my questions in the first place.

-- David