METHOD OF ROUTING FOR INTERWORKING BETWEEN LOCAL NETWORK AND GLOBAL NETWORK BASED ON SESSION INITIATION PROTOCOL, ALG DEVICE AND NAT DEVICE THEREOF

摘要

An SIP(Session Initiation Protocol) message routing method for SIP-based interworking between a private network and a public network, an application layer gateway device applied with the method, and an NAT(Network Address Translation) device are provided to suggest alterations necessary for an SIP message to solve an NAT-traversal problem of an SIP-based service, thereby being directly usable for development/implementation of a related node. A message transmission subject of a received SIP message and a method thereof are confirmed(S101). NAT based on the confirmed message transmission subject and method is applied to RTCP(Real Time Control Protocol) reception address information and media of the SIP message(S103). An address of a node selected on the basis of the confirmed message transmission subject is specified in routing path information of the SIP message(S105). The SIP message is routed to the corresponding destination address(S107).