Multicast control technique using MPLS

In this invention, an idea of the reverse direction label switched path (RLP) in Multi-Protocol Label Switching (MPLS) is applied to the multicast transmission to improve the management transmission in the multicast transmission, and to easily carry out an additional connection and disconnection. Specifically, in the reverse direction symmetric routing Label switched Path (LP), a virtual label in addition to an input label and an output label is used for the reverse direction routing. However, in this invention, instead of the virtual label, a multicast address to which a client terminal, which is connected to a head of the path on the reverse direction routing, and corresponds to a leaf in the multicast tree, is connected, is registered, as a multicast index, in routers on the path. Then, when receiving a multicast packet including a label and a multicast address, an output label corresponding to the received label is identified, thereby a destination link is identified.