>
> the encapsulation used by "remote interface switching" CCC is
> (as far as
> I can tell) just layer 2 in MPLS. No label stack, and nothing between
> the layer 2 frame and the MPLS header. I believe the FCS is stripped
> off. There's no plan AFAIK for this to be on the sandards track.
> Neither is it an implementation of Juniper's Layer 2 VPN draft.
>
Could be seen as early implementation of concept ;-), I think the
encapsulations are similar.
> The problem with CCC is that it doesn't scale. Each CCC connection
> requires 2 RSVP-signalled LSPs. This leads to an "n-squared" label
> problem in the core. So while CCC is useful for tunneling
> infrastructural services (e.g. Multicast, internal networks,
> etc.) over
> an MPLS core it isn't much use, in my opinion, if you want to provide
> services to customers :(
Since MPLS LSPs are uni-directional by definition, I would consider this
"scaling issue" an artefact of MPLS not CCC. But, you're right, it will kind
of a burden in large scale deployments. On the other hand, if you really
doing large scale L2 services ... why build an L3 network to provide this?
>
> A proposed "standard" for layer 2 over MPLS encapsulation is
> draft-martini-l2circuit-encap-mpls-00.txt (we are just putting 01.txt
> together now.) I would expect Juniper to implement this draft.
>
I suppose this also requires two LSP per circuit?
Apologies for not being completely familiar with this draft, but how do you
see this relate to mpls-l2vpn?
cheers,
Eduard
> Giles
>
> Darren Bolding wrote:
> >
> > Nikolas,
> >
> > Thanks for your reply! I think I understand what you are
> saying, especially
> > as regards using CCC for layer 2 switching cross-connects,
> or even for LSP
> > stitching.
> >
> > However, I use the word encapsulation for a couple of reasons:
> >
> > (1) Its the way Juniper describes it in the only reference
> I can find about
> > Ethernet VLAN-CCC
> >
> (http://www.juniper.net/techpubs/software/junos42/swconfig-int
> erfaces42/html
> > /interfaces-ethernet-config8.html) which I can only find in
> 4.2 docs (by
> > searching)
> >
> > (2) I'm particularly interested in MPLS LSP Tunnel Cross-Connects
> >
> (http://www.juniper.net/techpubs/software/junos43/swconfig43-m
> pls-apps/html/
> > ccc-config7.html#1013872). In this case, I would use
> encapsulation to
> > describe what's happening- ingress traffic on the interface
> is encapsulated
> > and put in an LSP, which travels across one or more LSR's
> to an egress point
> > where it is deencapsulated (with CCC, this is largely just
> stuffing frames,
> > but some layer-2 munging may occur).
> >
> > Am I missing something? I'd like to know if I
> misunderstand something.
> >
> > It seems odd that the 4.3 docs don't mention VLAN-CCC at
> all (that I can
> > find), I presume the functionality has not been deprecated.
> >
> > I'm interested in finding out if the method by which layer-2 data is
> > encapsulated and placed into an LSP is publicly documented,
> and if it is
> > standards track.
> >
> > Greg Ketell's e-mail implies that CCC is an implementation
> of the MPLS
> > Layer-2 VPN I-D. Which makes sense given the number of
> Juniper names on the
> > I-D. (Thanks Greg!)
> >
> > --D
> >
> > -- Darren Bolding darren@bolding.org --
> > -- http://www.bolding.org/~darren --
> >
> > > -----Original Message-----
> > > From: Nikolas Weidenbacher [mailto:nikw@sgns.net]
> > > Sent: Tuesday, January 30, 2001 4:07 PM
> > > To: Darren Bolding
> > > Cc: juniper-nsp@puck.nether.net
> > > Subject: Re: [j-nsp] CCC encapsulation standard?
> > >
> > >
> > >
> > > Encapsulation? CCC happens within a single router, so
> there is no such
> > > thing as a CCC packet. CCC is a configuration within the
> router that maps
> > > two logical interfaces together, or maps a logical
> interface to an MPLS
> > > tunnel.
> > >
> > > Are you sure you're not wondering about MPLS?
> > >
> > > Nik Weidenbacher nikw@sgns.net
> > > Network Engineer 215-351-1067
> > > Sungard Network Solutions
> > >
> > > On Tue, 30 Jan 2001, Darren Bolding wrote:
> > >
> > > >
> > > > Hello,
> > > >
> > > > I'm wondering if anyone can point me to any published
> standards for CCC
> > > > (Circuit Cross-Connect) encapsulation?
> > > >
> > > > I'm pretty sure its not in the ietf, but perhaps I missed it.
> > > I'm wondering
> > > > if Juniper has ever released the spec for
> interoperability purposes.
> > > >
> > > > Curious, and thanks,
> > > >
> > > > --D
> > > >
> > > > -- Darren Bolding darren@bolding.org --
> > > > -- http://www.bolding.org/~darren --
> > > >
> > >
> > >
> > >
>
> --
> ===================================================
> Giles Heron - IP Architect - Level 3 Communications
> phone: +44 20 7864 0719 mobile: +44 7880 506185
> ===================================================
>
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