Hi We need to develop a .NET application, basically a WinForms client, which needs to be notified of changes only from the server to update the UI only in case of necessity and not every time. We initially thought of NetTCPBinding but understood that it has problems with firewalls across domains and secure networks. We now consider long-polling as a viable option but we could only find this being used with WPF and XAML clients. For example, http://code.msdn.microsoft.com/duplexhttp But we could not find anything with WinForms. My opinion is that long-polling has to do with WCF and does not matter what UI technology is used (within .NET). Do you think it is possible to use long-polling with a custom WCF channel for WinForms? I am on the way to develop a POC but dont have much time. Any help in the right direction is much appreciated. Thanks much Charles