how can I test if a particular port is open on a server, particularly 1443?

Solution 1:

You can use a port scanning tool such as NMAP or just simply telnet to the port in question if it is a TCP port. telnet host port - Example would be telnet server01 1433

Solution 2:

First I'd verify that the server in question is actually listening on 1443. Simplest way to do that is probably (on the server, in a cmd window) netstat -an | find "1443" and see what you get back.

Second, if it's a TCP connection you're looking for, you may be able to telnet <hostname> 1443 and see if you get a connection. You won't be able to do anything with it, but that should tell you if you can establish one.

If you're looking for UDP, I'd be surprised if you had a good way to establish a connection on a connectionless protocol.