IEC 61400-25-5:2017 specifies standard techniques for testing of compliance of implementations, as well as specific measurement techniques to be applied when declaring performance parameters. The use of these techniques will enhance the ability of users to purchase systems that integrate easily, operate correctly, and support the applications as intended. This part of IEC 61400-25 defines: the methods and abstract test cases for compliance testing of server and client devices used in wind power plants; the metrics to be measured in said devices according to the communication requirements specified in IEC 61400-25 (all parts). This new edition includes the following significant technical changes with respect to the previous edition:- harmonization with structure and test cases in IEC 61850-10:2012;- reduction of overlap between standards and simplification by increased referencing to the IEC 61850 standard series.