"The present document contains the performance benchmark requirements applicable to IMS/PES/VoLTE exchange implementations based on Recommendation ITU-T Q.543 [1] and ETSI TS 101 563 [10]. The definitions of IMS/PES/VoLTE design objectives are based on ""best practice"" performance of legacy PSTN/ISDN signalling. The values contained in the present document are ""best practice"" performance values measured on IMS and PES implementations. The ISDN VGW values are based on carrier grade implementations."