Transport

Once a provider service is discovered by an airborne client, a WebSocket connection is maintained between the two to exchange data link messages. The provider client must expose two additional WebSocket endpoints, /cpdlc and /acars, for CPDLC and ACARS message exchange, respectively.

CPDLC

GET /cpdlc HTTP/1.1
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Protocol: fsdlp

ACARS

GET /acars HTTP/1.1
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Protocol: fsdlp