[c-nsp] MPLS down to the CPE

Richard Clayton sledge121 at gmail.com
Fri Jul 26 06:01:51 EDT 2013

They will always have a job for you there with that design.

On 25 July 2013 13:04, Adam Vitkovsky <adam.vitkovsky at swan.sk> wrote:

> I see so the islands are stitched together over the CsC L3VPN, since all
> islands have the same AS together they act like a common AS.
> And the CsC L3VPN is provided by the underlying common backbone
> Inter-AS-MPLS optC style.
> Right?
> So all access nodes within a particular island have RSVP-TE tunnels to
> ABRs/ASBRs within the island (ASBRs than provide connectivity to other
> islands).
> And there's a full mesh of tunnels between all ASBRs.
> Right?
> I'd like to ask is there a full mesh of iBGP sessions between the ASBRs or
> some of the ASBRs have a role of RRs please?
> So you have decided to create this sort of overlay AS dedicated for L2
> services.
> I think I understand your reasoning behind the setup and must say it's very
> bold and creative.
> See this is what I was talking about before, back in the old days engineers
> would have to get very creative and bold to create something extraordinary
> with such a limited set of features. With today's boxes you could all stack
> it up into a single AS not ever worrying about scalability or convergence
> times.
> Thank you very much for sharing the design with us
> adam
> -----Original Message-----
> From: Phil Bedard [mailto:philxor at gmail.com]
> Sent: Thursday, July 11, 2013 3:48 AM
> To: Adam Vitkovsky; mark.tinka at seacom.mu
> Cc: 'Andrew Miehs'; cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] MPLS down to the CPE
> On 7/10/13 4:16 AM, "Adam Vitkovsky" <adam.vitkovsky at swan.sk> wrote:
> >> the different network islands are tied together using CsC over a
> >> common MPLS core.
> >You got me scared for a moment CsC would mean to run a separate
> >OSPF/LDP/BGP-ASN for each area and doing MP-eBGP between ASBRs within
> >each
> >area(OptB) or between RRs in each area(optC) with core area/AS acting
> >as a labeled relay for ASBRs loopback addresses, though I believe by
> >common MPLS core you mean a single AS right please?
> The islands are actually all in the same ASN, the common core is not the
> same ASN.  Could have been the same ASN, more political reasons for it not
> being the same than technical.  In the end it looks like Option C, the CsC
> L3VPN only carries loopbacks and aggregate IP prefixes.   The common core
> is RSVP-TE based, if I had my preference today I would build TE tunnels
> across it between the islands and then use RFC3107 as a way to tie it all
> together end to end.  Years ago when we first built it some of the feature
> support wasn't there to do that.
> >
> >> At the ABR all of the L2VPN services are "stitched" since you are
> >> entering a different RSVP-TE/MPLS domain, the L3VPN configuration
> >> exists on these nodes with the access nodes using
> >> L2 pseudowires into virtual L3 interfaces.
> >I see, right that's a clever way to save some money by pushing the
> >L3VPN stuff to only a few powerful boxes with high-queue line cards and
> >L3VPN licenses. Though the PWHE -a setup where you can actually
> >terminate the PW into L3 interface on the same box was introduced to
> >Cisco boxes only recently so prior to that you'd have to have a
> >separate box bridging the PW to sub-int/serv-inst on a QinQ trunk where
> >the L3VPN box would be connected to.
> >
> >I'm still confused about the TE part.
> >So I believe you are pushing PW directly into TE tunnels what gives you
> >the ability to balance the PWs around the ring as well as to use a
> >backup tunnel via the opposite leg of the circuit. So the TE tunnels
> >are actually terminated on the PWHE nodes right? Or do they actually
> >continue into the backbone area please?
> The tunnels from the access boxes terminate on the PWHE nodes, they do not
> extend beyond that boundary.  There is another set of tunnels which connect
> the PWHE nodes together.  This isn't a one-off deployment or anything,
> there
> are other folks out there with basically the same type of deployment.
> Phil
> >
> >
> >adam
> >
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