[c-nsp] Backup methods in MPLS networks

[Oliver Boehmer (oboehmer)]

cisco-nsp-bounces at puck.nether.net <> wrote on Monday, January 08, 2007
9:38 AM:

> Hi,
> 
> I am confused with the different backup methods and
> technologies available
> and would like to just make it clear in simple terms (RSVP,
> LDP FRR, TE, LDP FRR, VPN FRR, IP FRR...)

Well, the terms "LDP FRR", "VPN FRR" don't exist per se.

> In an MPLS Core you can use MPLS TE FRR to make different
> LSPs(tunnels) to protect traffic coming from PEs incase of P router
> or link failure, correct?

Yes, MPLS TE FRR protects traffic sent via TE Tunnels by creating backup
tunnels for these TE tunnels.

> How about LDP FRR, IP FRR, VPN FRR ? what are they used for
> and what are the main diff. between each?

As mentioned, there is no LDP FRR and VPN FRR. MPLS TE FRR protects all
TE tunnels, so if you put VPN traffic into a TE tunnel, you can protect
this traffic as well (maybe you call this VPN FRR)

IP FRR is a new/emerging technology to protect also non-labeled IP
traffic. It uses pre-comupted backup paths much like TE-FRR, but doesn't
require the traffic to be TE-tunneled and doesn't use RSVP to set up the
path. There are several components to IP FRR, much of it is still being
debated within the IETF..

> In the case of a CE that has one link to 2 different PEs(dual homed),
> assuming one link is primary and the other is backup, which
> technology can we use to steer customer VPN traffic incase the
> primary PE node or link fails to the backup PE?

You need to use regular BGP attributes (like MED or localpref) within
the MPLS-VPN network.

	oli