+To identify performance changes due to VPP code changes from v20.01.0 to
+v20.05.0, both have been tested in CSIT environment ver. 4 and compared
+against each other. All substantial progressions has been marked up with
+RCA analysis. See Current vs Previous Release and Known Issues.
+
+CSIT environment ver. 4 has been evaluated against the ver. 2 by
+benchmarking VPP v20.01.0 in both environrment versions.
+
+.. include:: ../introduction/test_environment_intro.rst
+
+.. include:: ../introduction/test_environment_sut_conf_1.rst