This Recommendation defines speed, accuracy and dependability performance parameters that may be used in specifying and assessing the user information transfer performance of public frame relay data networks. The defined performance parameters are applicable to both PVC and SVC services.

This revision was undertaken to take into account the development of ITU-T Rec. X.147 which specifies network availability objective values together with techniques for assessing frame relay network availability. Information previously pertaining to availability has been moved to ITU‑T Rec. X.147. References have been updated to take into account the development of ITU‑T Rec. X.146 which specifies performance objectives and classes of service,  and of ITU‑T Rec. X.148 which defines measurement techniques.