Sending Spn in secured WCF Service

<endpoint address="" binding="basicHttpBinding" bindingConfiguration="basicHttp"
                name="BasicEndPoint" bindingNamespace="TestNamespace"
                contract="IService">
         <identity>
           <servicePrincipalName value="HTTP/TEST"/>
         </identity>
       </endpoint>

IService proxy = null;
ChannelFactory<IService> factory = null;
EndpointIdentity identity = null;
EndpointAddress address = null;
if (!string.IsNullOrEmpty(spnName))
    identity = EndpointIdentity.CreateSpnIdentity(spnName);//  < --- HARD CODE THE SPN VALUE HERE (HTTP/TEST)
if (identity != null)
    address = new EndpointAddress(new Uri(webServiceUrl), identity);  //< ----- PROVIDE THE SERVICE URL HERE
else
    address = new EndpointAddress(new Uri(webServiceUrl));  
factory = new ChannelFactory<IService>(bindingName, address);
factory.Credentials.Windows.AllowNtlm = true;
factory.Credentials.Windows.AllowedImpersonationLevel = System.Security.Principal.TokenImpersonationLevel.Delegation;
proxy = factory.CreateChannel();