CONTENTS

�1���� Scope
�2���� References
�3���� Definitions
�4���� Abbreviations
�5���� Conventions
�6���� General Frame Relay performance reference model
������� 6.1���� Frame Relay virtual connection portions and measurement points
�7���� Method for specifying availability
������� 7.1���� General definition of availability
������� 7.2���� Availability model
������� 7.3���� Definition of available/unavailable state
������� 7.4���� Methods for assessing availability
������� 7.5���� Availability parameters
�8���� Availability performance objectives
������� 8.1���� Availability Ratio
������� 8.2���� Mean Time Between Outages
Annex A � Determining availability states by use of performance parameter thresholds
������� A.1���� Frame Relay virtual connection availability
Annex B �Use of Frame Relay STATUS Messages or Alarm Indication as availability criteria
Annex C � Use of FR OAM non-latching loopback messages for estimation of Frame Relay connection availability when using connectivity as the outage criteria
������� C.1���� Introduction
������� C.2���� The declaration from connection available to connection unavailable
������� C.3���� The declaration from connection unavailable to connection available
������� C.4���� In-service estimation of availability
Annex D � Use of FR OAM to monitor Frame Loss Ratio in order to assess availability
Annex E � Calculation of Mean Network Availability Ratio based on the measurement of individual Virtual Connection Unavailability
Appendix I � Sampling estimation of PVC availability parameters
������� I.1���� �� A minimal test for PVC service availability
������� I.2���� �� Procedures for estimating PVC service availability
������� I.3���� �� Procedures for estimating mean time between PVC service outages