Navigil speaks sequenced binary on TCP 5025. NavigilFrameDecoder feeds NavigilProtocolDecoder, which acknowledges with reply headers (sendAcknowledgment) and parses several report classes: unit reports, TG2 reports, position report variants, snapshot4, and tracking data. Attributes include antenna state, battery/charge, satellite counts, odometer/distance, flags, and IO prefixes.
Sequence + ack discipline
Unlike fire-and-forget ASCII lines, Navigil’s open decoder expects sequenced frames and emits acknowledgments. Missing acks can stall a unit that waits for header confirmation.
Sibling contrast
Alematics on 5140 is $T, ASCII over a TCP string pipeline — not Navigil’s binary report catalog.
Catalogue stance
Traccar stock reference; Traxelio positions_only.