This Recommendation defines network performance parameters, objectives and measurement methods for describing the availability of Frame Relay networks. The specified parameters and objectives apply to international Frame Relay connection portions  National Portions, International Transit Network Portions and International Interoperator Portions. The objectives, which are worst-case values, are intended to assist service providers with network planning by limiting the aggregate effect of network impairments, including congestion, equipment failures and transmission errors.

A set of network objectives is specified which define the overall network performance based on a statistical sample of Frame Relay connections. The objectives do not apply to or define the performance of an individual Frame Relay connection.

A two-state availability model is defined along with criteria for determining if the service during specific periods of time should be declared to be either available or unavailable. A number of procedures are defined in order to assess the availability performance of virtual connections. An expression for determining a value for overall network availability is presented. Information for estimating availability from a minimal set of observations is also presented.