Dear Anupam,
I am also having this kind of issue: in proxy to web service scenario
Failed to call the endpoint: Error in call over HTTP: HTTP 0 null
SOAP: Call failed: java.io.IOException: Communication over HTTP. Unable to create a socket.
I can ping/telnet from my local computer. We can test with SOAP UI as well. But from PI only, we got the error. I have tried with anonymous login & user authentication config also. But it's failed.
Thanks!