Dualcam on Traccar TCP 5232 is a camera-oriented binary protocol (DualcamFrameDecoder + DualcamProtocolDecoder). Message types include MSG_INIT 0, MSG_START/RESUME/SYNC/DATA/COMPLETE, MSG_FILE_REQUEST 8, MSG_INIT_REQUEST 9, and path request/response 0x000C/0x000D. Settings bits choose %photof/%photor stills or %videof/%videor clips; completed media attaches as jpg or h265 via writeMediaFile, then often re-issues MSG_INIT_REQUEST.
Camera naming, media state machine
Not DSF22’s batched GNSS on 5236 — Dualcam’s identity is front/rear photo-video transfer on 5232.
Catalogue stance
Stock Traccar reference. Traxelio still lists positions_only for catalogue/BYOD identity (media plumbing ≠ Traxelio operator feature claim).