This Recommendation defines error performance parameters and objectives for international digital connections operating below the primary rate of the digital hierarchy, using equipment designed prior to the adoption of revised ITU-T Rec. G.826 on 14 December 2002. The objectives given are independent of the physical network supporting the connection. This Recommendation is based upon bit error and bit error ratio measurements. The events, parameters and objectives are defined accordingly. Annex A deals with the definition of availability of the connection.