[j-nsp] lsp required for vpls?

[Derick Winkworth]

MPLS does not "depend" on RSVP.  

MPLS itself has "multiple" layers.  The most basic model is the "transport" layer underneath an "application" layer.  This is the model many service providers use.

Each "layer" has its own signaling.  So, for instance, the transport layer in a service provider network gets traffic between the edges of the provider's network (PE to PE).  Routing between PEs is based on a routed loopback on each of the PEs.  At the transport layer, from hop-to-hop, signalling can be LDP or RSVP or even BGP (not VPNv4, but BGP signalled labels).

At the application layer (VPLS, L3VPN, etc), a second MPLS label is added.  VPNv4 is used between PEs to signal labels for L3VPN routes.  VPLS signals its labels with either "directed" LDP or BGP.  This label becomes the "inner" label of a dual-label stack.  The outer label is the transport layer.

Now you can have multiple transport layers for instance in the case of different Inter-AS options or CSC, if you are doing those things...  And in any case you can have multiple application layers running in parallel...

Juniper, of course, recommends RSVP for the transport layer so their troubleshooting documentation reflects that.  Cisco recommends LDP, which is a standard version of TDP which is Cisco proprietary.

I hope this helps.




________________________________
From: Simon Chen <simonchennj at gmail.com>
To: snort bsd <snortbsd at yahoo.com.au>
Cc: "juniper-nsp at puck.nether.net" <juniper-nsp at puck.nether.net>
Sent: Sunday, August 9, 2009 11:22:14 AM
Subject: Re: [j-nsp] lsp required for vpls?

According to this document, MPLS depends on RSVP...

http://www.juniper.net/techpubs/software/nog/nog-mpls-model/html/mpls-model2.html#1035142

I'm really confused and want to figure out exactly what the dependency is...

Thanks.
-Simon

On Fri, Aug 7, 2009 at 10:25 AM, snort bsd<snortbsd at yahoo.com.au> wrote:
>
> I think you got confused with concepts of signaling protocol and lsp istelf.
>
> mpls is foundation of all new technologies that rely on mpls label switching. but mpls lsp depends on signaling protocols such as rsvp or ldp for the label swapping. bgp is still the protocol that utilize the lsp (in the table inet.3).
>
> vpls can be implemented via either ldp based (martini) or bgp driven (kompella).
>
>
>
> --- On Fri, 7/8/09, Simon Chen <simonchennj at gmail.com> wrote:
>
>> From: Simon Chen <simonchennj at gmail.com>
>> Subject: Re: [j-nsp] lsp required for vpls?
>> To: "Harry Reynolds" <harry at juniper.net>
>> Cc: "juniper-nsp at puck.nether.net" <juniper-nsp at puck.nether.net>
>> Received: Friday, 7 August, 2009, 5:09 AM
>> Thank you all for the reply.
>>
>> Do I need to explicitly configure MPLS LSPs between the PEs
>> (using
>> protocols/mpls/label-swithing-path)? Or just configure RSVP
>> or LDP on
>> the PEs so that LSPs can be automatically established by
>> VPLS?
>>
>> Thanks.
>> -Simon
>>
>> On Thu, Aug 6, 2009 at 1:12 PM, Harry Reynolds<harry at juniper.net>
>> wrote:
>> > Ldp can both signal vpls (ldp based vpls control
>> plane) and establish lsps. You either single vpls with ldp
>> or bgp, and then transport via a lsp between pes. This
>> transport lsp can be rsvp or ldp signaled.
>> >
>> > Regards
>> >
>> >
>> >
>> > -----Original Message-----
>> > From: juniper-nsp-bounces at puck.nether.net
>> [mailto:juniper-nsp-bounces at puck.nether.net]
>> On Behalf Of Simon Chen
>> > Sent: Thursday, August 06, 2009 9:35 AM
>> > To: juniper-nsp at puck.nether.net
>> > Subject: [j-nsp] lsp required for vpls?
>> >
>> > Hi all,
>> >
>> > I read in the VPN configuration guide that LSPs
>> between PEs are required for VPLS. However, I am able to
>> establish a VPLS setup using LDP signalling, but without
>> MPLS-LSP between PEs.
>> >
>> > Does anyone know why? My guess is that LSP is only
>> required if you're going for the BGP signalling, but not
>> required if you're doing LDP.
>> > Can anyone clarify this?
>> >
>> > Thanks.
>> > -Simon
>> > _______________________________________________
>> > juniper-nsp mailing list juniper-nsp at puck.nether.net
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