Systems and methods implementing a protocol that provides reliable transport over a point-to-point link characterized by deep and sustained fades. Such a communications link may be a free space optical channel or may be a radio frequency point-to-point channel. Data frames are processed through a circular data buffer that operates in a round robin fashion at a transmission node. The coding and forward error correction processes allow for continued operation in spite of possible signal fades due to atmospheric turbulence or other causes. At a receive node, incoming data is also saved in a circular buffer. A re-acknowledgment list is maintained at the receive node for tracking recently received and decoded data. This allows for a new acknowledgment to be sent in the event that a previously sent acknowledgment failed to reach the transmission node.