When setting up a label switched path (LSP) in Generalized MPLS and
MPLS/TE networks, the completion of the signaling process does not
necessarily mean that the cross connection along the LSP have been
programmed accordingly and in a timely manner. Meanwhile, the
completion of signaling process may be used by applications as
indication that data path has become usable. The existence of this
delay and the possible failure of cross connection programming, if not
properly treated, will result in data loss or even application
failure. Characterization of this performance can thus help designers
to improve the application model and to build more robust
applications. This document defines a series of performance metrics to
evaluate the availability of data path in the signaling process.