MPLS Guide MPLS and RSVP-TE
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Detour LSP The LSP that is used to reroute traffic around a failure in FRR 
one-to-one backup. The term “detour LSP” should not be 
confused with the term “detour route”. Detour route is a general 
term that refers to any alternate route, while detour LSP is a 
specific term that applies to one-to-one backup.
DMP Detour merge point
In the case of one-to-one backup, this is an LSR where multiple 
detours converge. Only one detour is signaled beyond that LSR.
Disjoint See SRLG disjoint
Facility backup A local repair method in which a single bypass tunnel is used to 
protect one or more LSPs that traverse the PLR, the resource 
being protected, and the Merge Point (in that order). Facility 
backup is distinct from a one-to-one backup tunnel, which has 
one backup path per protected path.
MP Merge point
The LSR where one or more backup tunnels rejoin the path of 
the protected LSP downstream of the potential failure. The same 
LSR may be both an MP and a PLR simultaneously.
NHOP bypass tunnel Next-hop bypass tunnel
A backup tunnel that bypasses a single link of the protected LSP
NNHOP bypass tunnel Next-next-hop bypass tunnel
A backup tunnel that bypasses a single node of the protected 
LSP
One-to-one backup A local repair method in which a backup LSP is separately 
created for each protected LSP at a PLR
PLR Point of local repair
The head-end router of a backup tunnel or a detour LSP, where 
the term local repair refers to techniques used to repair an LSP 
tunnel quickly when a node or link along an LSP path fails
Primary path An LSP that uses the routers specified by the path defined by the 
primary path-name command
Protected LSP An LSP is protected at a given hop if it has one or more 
associated backup tunnels originating at that hop
Reroutable LSP Any LSP for which the head-end router requests local protection
Secondary path An LSP that protects a primary path that uses LSP redundancy 
protection rather than FRR protection
Table 6 FRR Terminology (Continued)
Term Definition