Solution:
On a Unix/NT host you can use the 'netstat -a' option to verify if the connection has been established or listening:
Example on a SCO host to check all TCP connection states for port 1000x:
# netstat -a | grep 1000
tcp 0 0 sco507.10002 js8500.3876 ESTABLISHED
tcp 0 0 *.10001 *.* LISTEN
tcp 0 0 *.10003 *.* LISTEN
udp 0 0 *.10002 *.*
In this example the local host "sco507" has established a socket connection using local TCP port 10002 with remote host "js8500" (which happens to be port 2 on a Jetstream 8500). TCP ports 10001 and 10003 are waiting for a connection.
Verify with the MAN pages on the exact syntax for your version of Unix.
Note: the Iolan+ terminal server has Statistics -> Users that will also indicate the connection status of it's ports. If the port has established a connection it state of the port will be: Talking to Host [IP address:TCP socket]
Keep an eye on the port LED's on the terminal server. If data is being transmitted by the port the LED will indicate this. If data is being transmitted but not recieved then check your cabling.