Re: Segment Routing

[steve ulrich <sulrich () botwerks org>]

sorry, yes. i was referring to SRTE wrt the pop operation.

in most of the implementations i've poked at, there is the ability to
specify a consistent label range, but it's not always the case.  SIDs are
not labels but they are encoded as labels.  i hope operators have the
option to configure common/consistent label ranges, but i don't necessarily
assume it.  tooling to resolve this will be required just as in the LDP
world.


On Tue, May 22, 2018 at 9:19 AM Saku Ytti <saku () ytti fi> wrote:

> Hey Steve,
>
> > the data plane behavior on LDP is swap oriented, while the data plane on
> SR
> > is pop oriented.  depending on the hardware capabilities in use this may
> > have (subtle) traffic engineering or diagnostic implications at a
> minimum.
> > folks will likely have to build tooling to address this.
>
> I think you're thinking of SR-TE, SR in normal LDP-like use case would be
> single
> egress label with swap on LSRs.
>
> Ingress PE would figure out label by using egress PE index as an
> offset to next-hop
> P's label range.
> Nexthop P would swap the label determining out label using same mechanism.
>
> I practice operators would configure same label range in every box, so
> swap would be
> from same label to same label. But that is purely due to operator
> configuration, and
> it's still swap.
>
> --
>   ++ytti


-- 
steve ulrich (sulrich@botwerks.*)