There is a simple way to see network connections on a windows workstation, no extra software is needed to install on the remote machine. You can use a PsExec tool from SysInternals to exec a command line on the remote workstation and the use a standard windows utility netstat. If you can telnet to the workstation then even local installation of PsExec won’t be necessary :).
psexec \remotemachine
netstat -o -a