Re: Carrier supporting carrier: Why not L2VPN?

Brian

I didnt get ur point that u r saying that

"Another issue could be that if the SP buying
transit is using IS-IS for their routing, there are some failure situations
of
VPLS pseudowires that IS-IS can't deal with because it doesn't have a
point-to-multipoint behavior like OSPF does."

Can u elaborate more on this point.

I know that ISIS doesn't have point to multipoint network type unlike OSPF.
Recently i was a part of massive implementation in ISIS with VPLS ad i dont
see any corn cases where VPLS fails with ISIS

What was the exact problem u r referring too ? Can u be a bit more specific.

VPLS PE should be part of same Bridge Domain and r u provisioning Point to
Multipoint LSPs which is not at all required in case of VPLS.

On Mon, Dec 31, 2012 at 4:09 AM, Brian McGahan <bmcgahan_at_ine.com> wrote:

> Cisco supports both VPLS BGP autodiscovery and H-VPLS. VPLS no doubt is
> worth
> looking at for certain applications, but for a service provider using it
> for
> long haul transport it might not be a good design option. As with anything
> there are always both pros and cons, where a major pro of VPLS is that
> it's a
> layer 2 extension as opposed to CSC which introduces more complexity in the
> layer 3 routing design, but a major con of VPLS is that it's Ethernet only.
>
> If an SP wants to use OC-192 or OC-768 POS as their long haul transport
> then
> this won't work with VPLS. Another issue could be that if the SP buying
> transit is using IS-IS for their routing, there are some failure
> situations of
> VPLS pseudowires that IS-IS can't deal with because it doesn't have a
> point-to-multipoint behavior like OSPF does.
>
> Brian McGahan, CCIE #8593 (R&S/SP/Security)
> bmcgahan_at_INE.com<mailto:bmcgahan_at_INE.com>
>
> Internetwork Expert, Inc.
> http://www.INE.com
>
> From: Adam Booth [mailto:adam.booth_at_gmail.com]
> Sent: Sunday, December 30, 2012 12:09 AM
> To: Brian McGahan
> Cc: John Neiberger; ccielab_at_groupstudy.com
> Subject: 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<mailto: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<mailto: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<mailto: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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-- 
Regards
Routing Freak CCIE#35889 (SPv3)
Blogs and organic groups at http://www.ccie.net