AX25 - AX.25 Amateur Radio Link-Layer Protocol#

Pure OCaml implementation of the AX.25 Link Access Protocol for amateur radio packet communications.

Supports:

• Callsign parsing and validation (with SSID 0-15)
• Address encoding/decoding with digipeater support
• Control field types: I, RR, RNR, REJ, UI, SABM, DISC, UA, DM, FRMR
• Protocol identifiers: No_layer3, IP, ARP, FlexNet, NET/ROM
• CRC-16-CCITT frame check sequence
• HDLC framing with bit stuffing
• KISS TNC protocol framing

Installation#

opam install ax25 will install this library.

Usage#

open Ax25

(* Create a UI frame *)
let src = callsign_exn ~call:"N0CALL" ~ssid:1
let dst = callsign_exn ~call:"CQ" ~ssid:0
let frame = ui_frame ~src ~dst (Bytes.of_string "Hello!")

(* Encode for transmission *)
let encoded = kiss_encode frame

(* Decode received frame *)
match kiss_decode data with
| Ok frame -> Format.printf "%a@." pp frame
| Error e -> Format.printf "Error: %a@." pp_error e

Reference#

• AX.25 Link Access Protocol Specification