25 PROTOCOL IMPLEMENTATION IN ELECTRONIC EQUIPMENT FOR DATA EXCHANGE. FIELD: electronic communication devices. SUBSTANCE: device has application level unit, transmission and session level unit, and multilevel X.25 unit. Goal of invention is achieved by control of state of data channel by means of transmission and session level unit. Application level unit transmits request signal for establishing virtual channel to packet-switching network through transmission and session level unit and multilevel X.25 unit. Called system receives request signal for establishing virtual channel through packet-switching network and outputs message on virtual channel establishing to multilevel X.25 unit of calling party through packet-switching network. Multilevel X. 25 directly transmits virtual channel establishing message to application level unit. Application level unit directly receives data to be transmitted to multilevel X.25 unit upon receiving confirmation message on virtual channel establishing. Multilevel X.25 unit converts transmission data to packets and transmits packets data to called system through packet-switching network. EFFECT: increased functional capabilities. 3 cl, 5 dwg
