In 1:N (N ≥1) protection, the protecting LSP path is a fully provisioned and resource-disjoint LSP path from the N working LSP paths. The N working LSP paths may also be mutually resource-disjoint. Coordination between end-nodes is required when switching from one of the working paths to the protecting path. Although RFC4872 allows extra traffic on the protecting path, this is not supported by the 7750 SR or 7950 XRS. Figure 1 illustrates this protection architecture when N=1, while Figure 2 shows the case for N>1.
Figure 1. 1:N Protection, with N=1 (RFC4872)
Figure 2. N>1 Protection
