To use this form, you need to know the IP Address (a name or a set of numbers) for the person with whom you want to communicate. Then you type in an Outgoing Message and click on Send Message. The event log reports whether the message was received/acknowledged. Messages that the other person sends you are posted in the Received panel.
This is just for testing communications. For actual 'conversations' during a game a different form (Chat) will be used, which is more user friendly.

