1. A network address translation traversal system for real-time communications, comprising: a user terminal equipment located in a private network; a network address translation device; a signaling control system located in a public network, being configured to instruct the network address translation device to create a network address translation mapping for a real-time communication connection; and a peer terminal located in the public network, being configured to create the real-time communication connection with the user terminal equipment via the network address translation device directly according to the network address translation mapping.