Configures default frame segmentation function (VortexChannelFrameSize) used for all connections and all channels that do not have a segmentator defined.
See vortex_connection_set_next_frame_size_handler and vortex_channel_set_next_frame_size_handler.
|next_frame_size ||The handler to be configured globally.|
|user_data ||User defined pointer to be provided to the global function to be configured.|
- Returns previously configured handler or NULL if nothing was set. The function does nothing and return NULL if connection reference received is NULL.