H3C Technologies H3C Intelligent Management Center - Manual (Page 193)

Figure 56 Protected Tunnel List section
3. Find the tunnel that you want to configure CR-LSP backup for, click Hot Backup in the CR-LSP
Backup Operation column to change the CR-LSP backup type if needed, and then click the CR-LSP
Backup Operation icon .
Two approaches are available for CR-LSP backup:
• Hot backup—Where a secondary CR-LSP is created immediately after a primary CR-LSP is
created. MPLS TE switches traffic to the second CR-LSP after the primary CR-LSP fails.
• Second backup—Where a secondary CR-LSP is created to take over after the primary CR-LSP
fails.
FRR
Fast Reroute (FRR) provides a quick per-link or per-node protection on an LSP.
In this approach, once a link or node fails on a path, FRR comes up to reroute the path to a new link or
node to bypass the failed link or node. This can happen as fast as 50 milliseconds thus minimizing data
loss.
Basic concepts
The following are FRR concepts:
• Primary LSP—The protected LSP.
• Bypass LSP—An LSP used to protect the primary LSP.
• Point of local repair (PLR)—The ingress of the bypass LSP. It must be located on the primary LSP but
must not be the egress.
• Merge point (MP)—The egress of the bypass LSP. It must be located on the primary LSP but must not
be the ingress.
FRR link protection and node protection
FRR provides link protection and node protection for an LSP as follows:
• Link protection, where the PLR and the MP are connected through a direct link and the primary LSP
traverses this link. When the link fails, traffic is switched to the bypass LSP. As shown in
Figure 57 ,
183