A network application such as the Digital Signage Network Management Agent (dsagent.exe) will listen for incoming connections on a specific port - in the case of the dsagent, this port number is by default 9000.

If a remote client application attempts to connect to the dsagent on a different port number, or if the dsagent is not running, the error message 'Connection refused. No connection could be made because the target machine actively refused it' is displayed.

Resolution
  1. Ensure that the DS Agent application is running.
  2. In the DS Agent application, click Configure and verify that it is listening on the same port number that you are attempting to connect to. The port number is listed as 'Enable RDMP connections on port' and the default port number is 9000.
  3. Ensure that the Windows firewall is either disabled, or an exception has been created for the port number that you are connecting to (https://www.howtogeek.com/howto/uncategorized/how-to-create-exceptions-in-windows-vista-firewall/)

WSAETIMEDOUT <=> firewall issue

WSAECONNREFUSED <=> no one's listening issue

In order to get the WSAECONNREFUSED error the remote machine has to have "actively refused" the connection. for TCP this means you could actually send a SYN packet but got an RST back. in practice this error occurs if nobody is listening on the TCP port that you're trying to connect to on the remote machine. In this case failure is immediate.

If you have a firewall configured to block traffic to the port you're trying to connect to, the SYN packet wil actualy be swallowed by the firewall and never replied to. in this case the client will resend the SYN packet a number of times an eventually will give up and return the WSAETIMEDOUT errror. in this case failure takes a long time, typically around 20 seconds.

Error codes are described in detail here: http://msdn2.microsoft.com/en-us/library/ms740668.aspx

WSAETIMEDOUT
10060
Connection timed out.
A connection attempt failed because the connected party did not properly respond after a period of time, or the established connection failed because the connected host has failed to respond.

WSAECONNREFUSED
10061
Connection refused.
No connection could be made because the target computer actively refused it. This usually results from trying to connect to a service that is inactive on the foreign host—that is, one with no server application running.