Traffic engineering (TE) broadly encapsulates both Layer 2 protection mechanisms as well as quality of service (QoS) mechanisms. The MPLS Topology Server supports the Layer 2 protection aspect of MPLS traffic engineering. It detects the following protection mechanisms on TE tunnels and performs impact analysis on the tunnels:

  • Link protection

  • Node protection

  • Path protection

    Link/node protection is a mechanism that locally repairs a primary TE LSP if a link or node in the LSP path fails. In contrast, path protection is a mechanism that routes traffic onto a secondary TE LSP when the primary fails.