Users, who have simultaneous access to a plurality of terminal devices, can enter into a multimedia, multiterminal user session. In a negotiation phase users agree on which media to use in a multimedia session and select the most appropriate types of terminal devices that support the selected media. Each terminal device is connected to one of a plurality of interworking communications networks. A network node (130) that is reached through any of the plurality of interworking networks manages creation and supervision of sub-sessions involving the selected terminal devices such that each type of terminal device carry at least one selected media. A versatile and media rich communication is obtained in which terminal devices currently available at a local environment are efficiently used.