Packet Radio AX25

Amateur radio version of CCIR recommendation X25 but with extended addressing fields. Transmission consists of packets of synchronous data transmission at 300 Baud (mainly on HF) and 1200 Baud at VHF. Every packet frame consists of a synchronising sequence, a start-flag, address field, actual data packet of up to 256 characters in ASCII then the CRC information and finally the stop flag.