WCF Response Disappears - HTTP/1.1 504 Fiddler - Receive Failure - [Fiddler] ReadResponse() failed:

[Selvakumar Murugesan]

I have WPF client which is talking to a WCF Service. On sending big request from the wpf client to WCF service, i am not getting back with the response from WCF sometimes. I am getting Null as response. Its look like data is being disappear on the wire and not sure about that. I have tried to enable WCF tracing and there is no exception in it :( Not sure what went wrong. I have increased the timeout in IIS to 900 seconds. But  no luck. I have increased the buffer size in bindings and all possible web.config settings and no luck. Any one can help me on this issue. Thaks a lot for your help in advance.