Connection refused could be a firewall issue.
Is this an outbound request from your DMZ or is someone trying to run a service on your IS?
yes it is an outbound request from our IS to external server.
When you say you login to your client’s server, what are you using to login, a web browser?
No, we have imported clients WSDL in our wM developer through the webService connector and we found a login service, through the developer we have given the input details(SOAP Request)
In that case connection refused usually means the host:port you are trying to connect to is either blocked or not the correct port.