A method for establishing a multi-cascade channel in a video and/or audio multipoint conference formed among at least a first multipoint control unit, MCU, and a second multipoint control unit, MCU, comprising: sending (2a01), from the first MCU to the second MCU, a request to obtain an audio, video or data stream of a site, wherein the request comprises at least one site identifier, as well as an address and a port where the first MCU will listen for the audio, video or data stream, wherein the site identifier comprises an MCU (501, 502) and a terminal (T1-T6); determining, by the second MCU, whether the site belongs to the second MCU, and in response to determining that the site does belong to the second MCU,establishing (2a02), according to encoding information of said audio, video or data stream, said address and said port, a multi-cascade channel for transmitting said audio, video or data stream; and sending (2a03), through said multi-cascade channel, said audio, video or data stream, characterized in that the method further comprises: in response to determining that the site does not belong to the second MCU, performing, by the second MCU, the following steps: determining a third MCU to which the site not belonging to the second MCU belongs; sending a request to obtain an audio, video or data stream to the third MCU, wherein the request includes the site identifier of the site not belonging to the second MCU; establishing a first multi-cascade channel for said audio, video or data stream with the third MCU; receiving the audio, video or data stream through the first multi-cascade channel, establishing a second multi-cascade channel with the first MCU, and forwarding the audio, video or data stream to the first MCU via the second multi-cascade channel. sending (2a01), from the first MCU to the second MCU, a request to obtain an audio, video or data stream of a site, wherein the request comprises at least one site identifier, as well as an address and a port where the first MCU will listen for the audio, video or data stream, wherein the site identifier comprises an MCU (501, 502) and a terminal (T1-T6); determining, by the second MCU, whether the site belongs to the second MCU, and in response to determining that the site does belong to the second MCU,establishing (2a02), according to encoding information of said audio, video or data stream, said address and said port, a multi-cascade channel for transmitting said audio, video or data stream; and sending (2a03), through said multi-cascade channel, said audio, video or data stream, characterized in that the method further comprises: in response to determining that the site does not belong to the second MCU, performing, by the second MCU, the following steps: determining a third MCU to which the site not belonging to the second MCU belongs; sending a request to obtain an audio, video or data stream to the third MCU, wherein the request includes the site identifier of the site not belonging to the second MCU; establishing a first multi-cascade channel for said audio, video or data stream with the third MCU; receiving the audio, video or data stream through the first multi-cascade channel, establishing a second multi-cascade channel with the first MCU, and forwarding the audio, video or data stream to the first MCU via the second multi-cascade channel. determining a third MCU to which the site not belonging to the second MCU belongs; sending a request to obtain an audio, video or data stream to the third MCU, wherein the request includes the site identifier of the site not belonging to the second MCU; establishing a first multi-cascade channel for said audio, video or data stream with the third MCU; receiving the audio, video or data stream through the first multi-cascade channel, establishing a second multi-cascade channel with the first MCU, and forwarding the audio, video or data stream to the first MCU via the second multi-cascade channel.