Outbound Data Polling System

File descriptors in the outbound file descriptors list are polled, in order, for data waiting to be sent. When a file descriptor is found to have data, a new formatted message is created if needed and data is read to fill the payload of that message from the file descriptor. The message type is indicated by the file descriptor's record in the outbound file descriptors list. The result of this operation is a formatted SteganRTP message ready for encryption and embedding into the cover-medium.