HTTP Status 502 : Proxy Error, for accessing a Web Services

Question

I am accessing a web Service in Internet, So that I created a class using wsdl (language:C#). When I am calling the web method, it return as "The request failed with HTTP status 502: Proxy Error ( Connection reset by peer. For more information about this event, see ISA Server Help. )." It's common accross all the web services. I passed the proxy name and port also. I increased the timeout period. Still I am facing the same problem. plz give a solution. thanx in advance Mohan kumar