Interworking of devices from other vendors

Hello,

I think to choose C.

Traffic engineering (TE) fast reroute (FRR) protects links and nodes on MPLS TE tunnels. If a link or node fails, TE FRR rapidly switches traffic to a backup path, minimizing traffic loss.

A link or node failure in an MPLS TE tunnel triggers a primary/backup CR-LSP switchover. During the switchover, IGP routes converge to a backup CR-LSP, and CSPF recalculates a path over which the primary CR-LSP is reestablished. Traffic is dropped during this process.

TE FRR can be used to minimize traffic loss. TE FRR establishes a backup path that excludes faulty links or nodes. The backup path can rapidly take over traffic, minimizing traffic loss. In addition, the ingress attempts to reestablish the primary CR-LSP.

TE FRR works in either facility or one-to-one backup mode.

• Facility backup

  illustrates facility backup networking.

  Figure 4-19 Schematic diagram for TE FRR in facility backup mode
  

  TE FRR working in facility backup mode establishes a bypass tunnel for each link or node that may fail on a primary tunnel. A bypass tunnel can protect traffic on multiple primary tunnels. TE FRR in facility backup mode is configured to establish a single bypass tunnel to protect primary tunnels. This mode is extensible, resource efficient, and easy to implement. Bypass tunnels must be manually planned and configured, which is time-consuming and laborious on a complex network.

• One-to-one backup

   illustrates one-to-one backup networking.

  Figure 4-20 Schematic diagram for TE FRR in one-to-one backup mode
  

  TE FRR in one-to-one backup mode automatically creates a backup CR-LSP on each node along a primary CR-LSP to protects downstream links or nodes. This mode is easy to configure, eliminates manual network planning, and provides flexibility on a complex network. However, this mode has low extensibility, requires maintenance of the backup CR-LSP status on each node, and consumes more bandwidth than the facility backup mode.

• Hope to help you!

VPN FRR

MPLS TE FRR protects services in case a link or node fails between two PEs at both ends of a TE tunnel. MPLS TE FRR, however, cannot protect services in case a PE device fails. If a fault occurs on the ingress or egress, services can only be restored through end-to-end route convergence and LSP convergence. The service convergence time is closely related to the number of routes inside an MPLS VPN and the number of LSP hops on the bearer network. More VPN routes mean longer service convergence time and more lost traffic.

VPN FRR sets forwarding entries in advance that point to active and standby PEs on a remote PE. VPN FRR collaborates with fast PE fault detection to reduce end-to-end service convergence time if a fault occurs in an MPLS VPN (where a CE is dual-homed to two PEs). In VPN FRR, service convergence time only depends on the time required to detect remote PE device faults and change tunnel status. The service convergence time is not affected by the number of VPN routes because of VPN FRR.