IS-IS TE Extension

To help provide traffic engineering and MPLS with information about network topology and loading, extensions have been added to the implementation of IS-IS on Juniper devices. Specifically, IS-IS supports new type, length, and value (TLV) tuples that specify link attributes. These TLVs are included in the IS-IS link-state PDUs. The link-attribute information is used to populate the traffic engineering database, which is used by the Constrained Shortest Path First (CSPF) algorithm to compute the paths that MPLS label-switched paths (LSPs) take. This path information is used by RSVP to set up LSPs and reserve bandwidth for them.