即使服务正在运行，DuplexProxy也无法调用wcf服务协定

Question

我们有wcf服务，该服务在净tcp绑定上运行并具有回叫合同。 当我尝试使用双工代理通道调用服务方法时，出现以下错误。服务正在运行，但无法与代理客户端连接。

C＃

this.Invoke(p => p.Subscribe(), true);

public void Invoke(Action<T> call, bool keepOpen)
{
    T proxy = GetProxy();            
    call(proxy);
}

public T GetProxy()
{
    NetTcpBinding binding = new NetTcpBinding("");                   
    EndpointAddress address = new EndpointAddress(new Uri("net.tcp://" + Server + RelativeUrl), EndpointIdentity.CreateSpnIdentity(Server + "/" + Environment.MachineName));
    factory = new DuplexChannelFactory<T>(new InstanceContext(callbackInstance), binding, address);
    T proxy =  factory.CreateChannel();
    ((IClientChannel)proxy).Open(); 
    return proxy;
}

服务

[ServiceContract(SessionMode = SessionMode.Required, CallbackContract = typeof(IWorkflowChanged))]
public interface IWorkflowChangedPublisher
{
    [OperationContract(IsOneWay = false)]
    void Subscribe();
}

public interface IWorkflowChanged
{
    [OperationContract(IsOneWay = true)]
    void WorkflowChanged(WorkflowChangedEventArgs args);
}

得到以下异常：

Server stack trace: 
at System.ServiceModel.Dispatcher.DuplexChannelBinder.SyncDuplexRequest.WaitForReply(TimeSpan timeout)
at System.ServiceModel.Dispatcher.DuplexChannelBinder.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]:  

at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at Tradar.Workflow.Service.IStatusPublisher.Subscribe()
at Tradar.Workflow.StatusMonitor.<>c.<Open>b__16_0(IStatusPublisher p) in D:\PMARepo\backoffice\Insight\Modules\Workflow\Core\StatusMonitor.cs:line 139
at Tradar.Workflow.ProxyFactory`1.Invoke(Action`1 call, Boolean keepOpen) in D:\PMARepo\backoffice\Insight\Modules\Workflow\Core\ProxyFactory.cs:line 79