Standard UML ports
Recognisable with the lollipop and cup symbology, the lollipop tells us the port is contracted to provide the iSubsystem interface.
The cup tells us that it requires the iConsoleAck interface.
The «interface» is a type of class in UML that lists the signatures of operations provided independent of implementation.
This notation is core to component-based design of software with UML2, hence works well with software-centric system modelling. Although deprecated from SysML it remains important in UML, and is still widely used in SysML and systems models, due to its flexibility and power. For example, a single port can provide or require multiple interfaces
If you make use of these, then you may also find you are making use of object-orientated features of UML (such as polymorphism). For example, a behaviour port is one where the Block itself will realize the provided interfaces on the port.
SysML proxy ports
As with UML and pre SysML 1.3 ports, the ~ tells us that this port is ‘conjugated’, i.e. it mirrors or provides the reverse of the interface.
Unlike the UML port we can also show data or object flows, not just operations and invoked behaviors. For example, if we add flow properties then we can see that a direction indicator is also shown.