The MPLS WG Archive

["Brijesh Kumar" <bkumar@ennovatenetworks.com>]

In his previous message, Sean Doran writes

> -----Original Message-----
> Martin Cooper <mjc@cooper.org.uk> writes:
>
> > the de-coupling of end-to-end path-selection from the
> > extremely dynamic hop-by-hop routing information
>
> MPLS is a condensation of a GRE-like data-in-IP
> encapsulation header, plus some related control planes to
> lay out an SSR (strict source route) across a routed,
> packet-switched network.
>
> > On the other hand, destination-prefix based IP routing
> > is quintessentially a hop-by-hop algorithm
>
> How is MPLS any different?

You are absolutely right.

When MPLS work started the enhancing the speed of IP route look up was a key
motivator behind the technology.  IP route look up speed no longer being an
issue in core gateways, it doesn't really matter if you provision your
source routes using CR-LDP for certain traffic (or whatever else you have),
or by going to each router in the network and creating suitable entries
(manually or auto-magically under the control of a TE process) in the
routers so that a particular class of traffic goes over a statically
configured path. If there are no  traffic engineering requirements, as you
rightly pointed out, MPLS will not bring any additional benefits that can't
be provided using other technologies. But the core assumption is, lots of TE
is required.

Cheers,

--brijesh