The Ports dialog box is opened when you click on the Ports button in the Ports section of the Cadence Virtuoso main interface window. This dialog box lists all the Cadence pins in your Virtuoso SonnetEM view, which are automatically translated to Sonnet ports, and the Sonnet parameters to be used to represent them. To change the port parameters, either click on an entry to select it, then click on the edit button or double-click on an entry; either action opens the Edit Port dialog box to edit the selected port's properties.
To add a new port, you need to add a pin to the Cadence layout.