This is not an error. GuiXT uses the SAP RFC, which in turn uses the
TCP/IP protocol. When the RFC connection is closed, the underlying TCP/IP connection is not closed immediately with it.
Instead, it goes into the state "TIME_WAIT", typically for around 2 minutes,
probably in order to wait for some unusual response in which case the data package
would need to be sent again. The TCP port is temporarily blocked, so a new TCP connection will use
a new port number which you can see with netstat. There are enough port numbers available, so this
causes no problems. If you wait a couple of minutes, and then do the netstat again, no
TIME_WAIT connections will be there, and the ports are available for new connections.