Devang,

MPLS FRR is implemented in two main categories: one-to-one backup (detour LSPs) and many-to-one backup (facility backup).

With one-to-one backup, a separate backup LSP is setup on each intermediate hop (except for the penultimate hop) for each LSP that is configured for one-to-one backup. The drawback is that it doesn't scale to well given the fact that the backup tunnels are dedicated to one LSP instead of being shared by multiple LSPs.

With facility backup, backup tunnels are used to protect many LSPs. The drawback is that the backup tunnel needs to be manually configured for each facility (link or node) that needs to be protected.

Cisco IOS implements facility backup.

Please refer to RFC4090 for more information.

Hope this helps,