It could be your ISP blocking. But it also could be the server which is out of your hands.
QUOTE
Signals that an error occurred while attempting to connect a socket to a remote address and port. Typically, the connection was refused remotely (e.g., no process is listening on the remote address/port).
QUOTE
Either restart WebLogic Server, or contact the Web service host and ensure that the Web service is reachable.
More info:
http://www.desknow.com/kb/idx/0/027/article/