Rediscovery via SWIS

Hi all,

I wonder how to rediscovery nodes via SWIS. I tried that below code but I got error.

                var swis = new InfoServiceProxy(address, binding, credentials);

                XmlDocument xdoc = new XmlDocument();

                XmlElement[] elem = new System.Xml.XmlElement[1];

                XmlElement xel = xdoc.CreateElement("NetObjectID");

                xel.InnerText = "N:" + nodeID.ToString();

                elem[0] = xel;

                swis.Invoke("Orion.Nodes", "Rediscovery", elem);

Error:"Verb Orion.Nodes.Rediscovery: Not found"

Can you help me about this?