Below are the JAVA API's to modify the load and loadunit of a streamblock: To configure traffic generator as rate based: String hGenerator = stc.Get(hPortTx, "children-Generator"); String hGeneratorConfig = stc.Get(hGenerator, "children-GeneratorConfig"); stc.Config(hGeneratorConfig,sm); sm.clear(); sm.put("SchedulingMode","RATE_BASED"); To modify load and load unit of streamblock: String hStreamBlock1 = stc.Create("streamBlock", hPortTx); String Streamblockloadprofile1 = stc.Get(hStreamBlock1, "affiliationstreamblockloadprofile"); stc.Config(Streamblockloadprofile1,sm); sm.clear(); sm.put("load","10"); sm.put("LoadUnit"," PERCENT_LINE_RATE ");