I have a problem with the W3PROXY service, it responds to the clients: HTTP 503 Proxy is busy - A connection to the server could not be made because the limit on the number of concurrent connections for this account has been reached. (1238) The server is also a DC in win2003 native mode IIS Installed. Tried also the recommendations * The registry key for DisableBacklogMonitor = 1 (DWORD) * The Disabling the socket pooling for the IIS. * The performance tuning for the ISA. Additional information: If check the app filter (HTTP Redirector) to route the request directly to the server it works, so it bypass the proxy. Any help would be very usefull. Thanks. Gabriel Zabal Gabriel@xxxxxxxxxx