Method and system for bidirectionally transmitting message in MPLS (Multi-Protocol Label Switching) network

The invention discloses a method for bidirectionally transmitting a message in an MPLS (Multi-Protocol Label Switching) network, which mainly comprises the following steps of: establishing a P2MP (Point-to-Multipoint) LSP (Label Switching Path) with a forward path and a backward path between an Ingress PE node of the MPLS network and at least one Egress PE node, wherein the node through which the backward path passes is the same as that through which the forward path passes; when the Ingress PE node receives a message transmitted by a user side, transmitting the message to each Egress PE node along the forward path of the P2MP LSP; and when the Egress PE node receives the message transmitted by the user side, transmitting the message to the Ingress PE node along the backward path of the P2MP LSP. The invention further discloses a system for realizing bidirectional transmission of the message in the MPLS network. According to the invention, the management complexity of the LSP in the MPLS network can be greatly reduced; in addition, the method and the system can be applied to clock synchronization of IEEE (Institute of Electrical and Electronic Engineers) 1588v2; and on the premise of ensuring the clock precision, the number of intermediate transmission nodes by which the IEEE1588v2 can span between a main clock and a slave clock is not limited.