Patent ID: 7266124

Claim:
A method for setting up an L2VPN (Layer-2 Virtual Private Network) bi-directional tunnel using an extended LDP (Label Distribution Protocol) in a network providing MPLS (Multi Protocol Label Switching) based L2VPN service, which includes a plurality of VPN provider edges (PEs), a plurality of VPN customer edges (CEs) connected to the PEs and a VPN DNS (Domain Name Service) server for managing PE information associated with a plurality of VPNs, comprising the steps of: a) registering corresponding VPN information in the VPN DNS server if a CE belonging to a specific VPN is added to a first CE; b) where the first PE sets up a tunnel for the added CE, requesting the VPN DNS server to transmit information associated with at least one other PE belonging to the specific VPN and receiving the information associated with the at least one other PE as a result of the request; c) allowing the first PE to check whether a basic session between the other PE and the first PE exists, allowing the first PE to set up a new basic session for the other PE to transmit a label mapping-request message, simultaneously containing a label distributed for a uni-directional tunnel connection and a label request, to the other PE if the basic session between the other PE and the first PE dose not exist, and setting up the uni-directional tunnel connection directed to the first PE from the other PE; and d) allowing the other PE, receiving the label mapping-request message from the first PE, to transmit a label-mapping message having a label to be distributed to the first PE and setting up a uni-directional tunnel connection directed to the other PE from the first PE.