Abstract: A method is described for transmitting a multimedia stream from a first terminal and receiving an associated second multimedia stream at a second terminal. The first and second terminal are connected to at least one gateway for enabling the transmission of the stream and the receiving of the associated stream. The method comprises: initiating the exchange of first multimedia session information between the first terminal and the gateway, using a first protocol; providing a trigger to the second terminal to initiate the exchange of second multimedia session information between the second terminal and the gateway, using a second protocol; in response to providing the trigger, the second terminal initiating the exchange of second multimedia session information between the second terminal and the gateway, using a third protocol; transmitting a first multimedia stream from the first terminal and receiving a second associated multimedia stream at the second terminal.