FIELD: communication network technologies.
SUBSTANCE: technical result is achieved by a network device for controlling call between user terminals, configured to check whether or not the first user terminal supports use of the first audio coding mode for calling and whether the second user terminal intends to use the second audio encoding mode for the call; check whether the first initial call proposal sent from the calling user terminal to the called user terminal indicates whether or not to use the second audio encoding mode for the call; check whether the first response to the second initial call proposal sent from the called user terminal to the calling user terminal indicates whether the first audio encoding mode is used for the call.
EFFECT: technical result consists in providing communication between user terminals with higher stability and high quality of speech and audio signal.
12 cl, 3 dwg
