The MPLS-OPS Archive

[Robert Raszuk <raszuk@cisco.com>]

Wulf,

> Now, the next question is, under what circumstances would it be better to
> use a loose route vs. a strict route? Can anyone on the list clarify?

It's not the question of loose ERO object be better or not. Under some
network scenarios (for example inter-area TE) you just don't know the
topology of other area and can't calculate on the headend all stric
objects all the way to the tail. 

You have two options then:

A) use loose objects and relay on netowrk elements in the path to the
tail end to calculate portions of the ERO 

B) query different netowrk elements from the head end (Path Computation
Servers as example) and insert all stric objects once you get all
replies. 

Cheers,
R.


> Wulf Losee wrote:
> 
> Alexandre:
> Strict and loose routes are subcategories of explicit routes -- which is a
> route specified as a list of hops that must be part of the route (but not
> necessarily all of the route) used. A If an explicit route is strict,
> *only* the specified hops may be used. Note: a hop can be a node, an
> abstract node, or an Autonomous System. And in a strict route, the hops
> must be used in the order specified by the route.
> 
> If an explicit route is loose, all specified hops must be included in the
> resulting path, but the path is otherwise unrestricted -- in other words, a
> loose route must include all of the hops specified, and must maintain the
> order, but it may also include additional hops as necessary to reach the
> hops specified.
> 
> And once a loose route has been established it can be modified (as a
> hop-by-hop route could be) or it can be "pinned" so that it does not change.
> 
> Now, the next question is, under what circumstances would it be better to
> use a loose route vs. a strict route? Can anyone on the list clarify?
> 
> cheers!
> --Wulf
> 
> At 07:04 PM 1/30/03 -0300, Alexandre Carlos wrote:
> >Hi all,
> >
> >Can some one explain to me what what is a strict route and a loose one?
> >
> >Alex
> >
> >-------
> >The MPLS-OPS Mailing List
> >Subscribe/Unsubscribe:  http://www.mplsrc.com/mplsops.shtml
> >Archive: http://www.mplsrc.com/mpls-ops_archive.shtml
> 
> -------
> The MPLS-OPS Mailing List
> Subscribe/Unsubscribe:  http://www.mplsrc.com/mplsops.shtml
> Archive: http://www.mplsrc.com/mpls-ops_archive.shtml

-------
The MPLS-OPS Mailing List
Subscribe/Unsubscribe:  http://www.mplsrc.com/mplsops.shtml
Archive: http://www.mplsrc.com/mpls-ops_archive.shtml