Telephone (D-network), function schematic - GF82.70-P-0003-02R

with code 853/854 

Function schematic, permanently installed telephone 

Fig 1: Telephone (D-Network) - Communication Diagram (Permanently Installed Telephone)

Output from the hands-free system is accomplished via the entire loudspeaker system

Function schematic for portable cellular telephone 

Fig 2: Telephone (D-Network) - Communication Diagram (Portable Cellular Telephone)

Output from the hands-free system is accomplished via the entire loudspeaker system