HI,
Try hitting the below URL in a browser and you should be presented with xml content. If you get the result that means the wsdl is working and you your code should work as well. Otherwise you need to look into the IS if it is accessible and communication from MWS box to IS is 24/7.
10.21.32.75/ws/Cms_PriSeIntegration.wsd:Cms_PriSeIntegration?wsdl