Method of fallback from a multimedia connection set-up request to an audio connection set-up request by determining the capacity of the connection at the called end

摘要

A communications installation includes at least one cellular communications network that does not have an NGN architecture and to which communications terminals are connected. When the installation receives (F 1 ), from a calling mobile terminal (T 1 ), a request to set up a multimedia connection with a called terminal (T 2 ), it attempts to set up that multimedia connection (F 3 -F 4 ) and, if it fails to do so, it attempts to set up an audio connection between the calling and called terminals (F 5 -F 9 ).