Hello Olaf,
the ports of the Globallistener process (introduced with MaxDB 7.8 and higher) for TCP, NI, SSL cannot be changed.
Then you have the TCP port for each x_server installation. Every time you install a new database, a new port for the x_server gets assigned. Depending on the installation type, it should give you the option to chose the port you want to use.
However, it should also be possible to reassign/change existing x_server ports by editing the database installation file:
On Windows, it is located in the Registry "HKEY_LOCAL_MACHINE\SOFTWARE\SAP\SAPDBTech\Installations...", for the Unix types we keep it in the "Installation.ini" file.
Regards,
Thorsten