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Well off the original thread topic... draft-bonica-tunneltrace-02



Title: Well off the original thread topic... draft-bonica-tunneltrace-02

Hi Giles...long time no hear...;-)

Another thread I have my regrets about....comments in line...

<snip>
>
> Actually there are other things you can do with "just" LDP that you
> can't do with IP.
>
> 1)  draft-martini etc.  Sure, IP equivalents of this are now being
> defined (UTI^H^H^H L2TPv3 et al) but they aren't as widely available,
> and are much less efficient encapsulation-wise (as they require an IP
> header plus a tunnel header instead of a couple of labels).

If you're discussing:
- i) using extended LDP adjacencies to hand out PW labels
- ii) the relative effy. of MPLS labels vs. IP headers
no argument, but that is somewhat orthogonal to the discussion of the value that LDP-DU tied to routing may or may not provide.

>
> 2)  MPLS VPN (RFC2547).  I won't go into the pros and cons of
> this right
> now ;-)

Current implementation is MPLS but I don't think there is a sustainable dependency there...LDP permits the undelying MPLS network to behave like an IP network. Seems to me they should be interchangable.

> 3)  BGP free network core.  This may improve stability
> (though there's
> certainly a strong argument that BGP is less destabilising than LDP
> right now) and security (the core doesn't need to know how to
> get to the
> Internet.)  Also this allows you to layer multiple distinct
> IP backbones
> over one MPLS core.

Left that one out of my analysis, not sure how simple LDP helps here. I thought you LSP meshed your BGP speakers (which would be explicit routes) and eliminated IGP.

> > It is when I get into topology manipulation independent of dynamic IP
> > routing that MPLS starts to add value and to claim this is not
> > connection oriented use of MPLS forwarding IMHO smacks of the same
> > "tunnel"/"layer" semantic debate that can also be said to
> waste much time.
>
> this is your view.  And it is certainly one view.  But it isn't
> necessarily the only valid view ;-)

The "topology manipulation" part or the "terminology part" ? ;-)

later
Dave