[j-nsp] P2MP LSP

David water dwater2010 at gmail.com
Wed Jun 30 14:44:12 EDT 2010


Mark,

So from your replies: it look like we have already provisioned P2MP tunnel
right? Then in document they talk about static lsp and dynamic LSP
configuration then what is it all about?

Now about PMSI attribute if tunnel is already built then why do we need to
communicate the PMSI information? Still bit confused about the PMSI
attribute usage.

David W.

On Wed, Jun 30, 2010 at 4:33 AM, Mark Tinka <mtinka at globaltransit.net>wrote:

> On Wednesday 30 June 2010 03:18:34 am David water wrote:
>
> > Using those route types we can communicate about the
> >  source and destinations in MVPN.
>
> Source information is learned by the Sender PE router. This
> can either be through the VPN C-RP infrastructure or MSDP.
>
> Receiver PE routers would then use this information to
> generate Type 5 Source Active AD (Auto-discovery) routes.
> These routes allow the Receiver PE routers to identify
> active Multicast sources.
>
> Ideally (I say ideally because we had some nasty bugs in our
> case), this would then lead to the generation of Type 7
> Source Tree Join routes on the Receiver PE routers, assuming
> the router learns of C-join information, e.g., static IGMP
> configuration, or has a Type 6 Shared Tree Join route and
> receives a Type 5 route.
>
> You can reference this entire process in the documents I
> sent you earlier.
>
> >  Now as we know how to
> >  discover the source and receiver its time for RSVP to
> >  take care of building the P2MP right?
>
> It doesn't necessarily happen in this sequence.
>
> P-tunnel setup, i.e., association of a p2mp LSP with the RSI
> carrying MCAST-VPN NLRI would be part of your standard
> configuration when implementing BGP/MPLS NG-MVPN's.
>
> The PMSI attribute allows the P-tunnel to be announced in
> the network via BGP. When the Receiver PE routers receive
> this information, they bind the P-tunnel to the correct RSI
> that imported it. Once the P-tunnel is bound to the right
> RSI, the Receiver PE router can forward the Multicast
> traffic into the local VRF, using MPLS.
>
> Again, see those documents I sent. They get into very good
> detail about the process.
>
> >  So RSVP does use
> >  the the BGP discovered information to establish LSP,
> >  correct? So this way LSPs are totally dynamic.
>
> Not quite - the p2mp LSP's are setup by hand. BGP is just
> used to distribute control plane information about Multicast
> routing data. Once the control plane provides sufficient
> information, traffic is forwarded down the pre-setup p2mp
> LSP's (MPLS data plane).
>
> If you're looking at dynamic p2mp LSP setup, consider mLDP
> (Multicast LDP). Like in regular LDP for unicast
> applications, it's dynamic.
>
> I don't have any solid details yet on Juniper's plans re:
> mLDP, but I know Cisco are pushing this very heavily, along
> with some other options to using BGP as a replacement for
> PIM.
>
> Good times ahead between Juniper and Cisco, in this space
> :-).
>
> Cheers,
>
> Mark.
>



-- 
David W.


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