Hello, We are using Microsoft ISA Server for Web proxy. There is also another firewall at front of ISA. We use http,https and ftp without any problem. But our users need some other application to use different ports. For example. There is a web site using, IBM Host On Demand application needs TCP ports 8989,8999,12173,12174. I opened all ip traffic from protocol rules at ISA Server, but it did not work. ISA is installed on integrated mode. Clients are using manuel proxy configuration. Problem is not restricted with Host On Demand. MSN Messenger is not also working via my proxy. Best Regards Oguzhan