When the messages are being sent from the Panel itself i.e. the Web interface, then it is considered as Upstream. Whereas, when the messages are being sent from ESME to the iTextHub panel then it is considered as Downstream.
When the messages are being sent from the Panel itself i.e. the Web interface, then it is considered as Upstream. Whereas, when the messages are being sent from ESME to the iTextHub panel then it is considered as Downstream.