Handler definition for the set of functions that allow the users space to control how frames are splited by the vortex sequencer process.
This handler is used by the following functions:
|channel ||The channel that is required to return next frame size.|
|next_seq_no ||This value represent the next sequence number for the first octect to be sent on the frame.|
|message_size ||This value represent the size of the payload to be sent.|
|max_seq_no ||Is the maximum allowed seqno accepted by the remote peer. Beyond this value, the remote peer will close the connection.|
|user_data ||User defined pointer passed to the handler when it is executed.|
- The amount of payload to use into the next frame to be built. The function will return -1 if the channel reference received is NULL.