Re: Carrier supporting carrier: Why not L2VPN?

Hi Brian,

I would agree that vanilla VPLS has scaling problems compared to other
options such as CSC but there are ways to enhance it to be worth looking at
it. VPLS using BGP Auto Discovery should overcome the control plane
scaling and provisioning headaches and using PBB with H-VPLS would overcome
the forwarding plane scaling limitations. I'm not so sure about Cisco (and
would be surprised if they didn't have the facility) but I know that
Alcatel-Lucent and I think Juniper support these methods.

Cheers,
Adam

On Sun, Dec 30, 2012 at 1:23 PM, Brian McGahan <bmcgahan_at_ine.com> wrote:

> It is a corner case design. Most SPs would buy lambdas on someone else's
> DWDM network or MPLS L2VPN etc. Routing at layer 3 through another SP
> overcomplicates the design.
>
> It's the same as like Inter-AS MPLS L3VPN option C. Just because you
> *can* do it doesn't mean you *should* do it.
>
> Personally I've never seen any SP run option C, and I've seen many many
> large implementations. I'm sure it's out there and maybe someone here on
> the list has seen it but the amount of politics and interoperability that's
> needed between the providers is the limiting factor.
>
> From a technology standpoint CSC and option C L3VPN are more scalable than
> dark fiber or DWDM or L2VPN AToM or VPLS, but from an operational point of
> view a lot of time they're just not practical.
>
>
> Brian McGahan, CCIE #8593 (R&S/SP/Security)
> bmcgahan_at_INE.com
>
> Internetwork Expert, Inc.
> http://www.INE.com
>
> On Dec 29, 2012, at 8:00 PM, "John Neiberger" <jneiberger_at_gmail.com>
> wrote:
>
> > I'm watching some videos for the SP track and I just started one on CSC
> > using L3VPN. It seems awfully complicated. I haven't even really gotten
> > into the configuration of it yet, so maybe I'll be able to answer my own
> > question shortly, but why not just use L2VPN for this? It seems like you
> > could accomplish basically the same thing with MPLS pseudowires or
> > something like that. Or maybe even VPLS or whatever. Not sure about that
> > since I haven't done VPLS yet. :-)
> >
> > So, what's the deal? What advantage does CSC via L3VPN bring that would
> > make it worth all the configuration hassle?
> >
> > Heck, why not just run MPLS over GRE?
> >
> > I'll keep watching the video and reading about it. There is probably some
> > huge advantage that I am completely missing. I'm a noob to some of this,
> so
> > go easy on me. :)
> >
> > John
> >
> >
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Received on Sun Dec 30 2012 - 16:09:05 ART