The port to use to connect to IBM WebSphere Application Server based on the "Connector Type" specified.
If you're deploying to WebSphere ND, you should point to the deployment manager's configured port for the specified "Connector Type".
WebSphere ND's default SOAP port, or instance, is 8879. Whereas, standard WebSphere's default SOAP port is 8880. Check your WebSphere administration console or integrated solutions console for port information.