A method, apparatus, and system for remotely managing a private network by using a Session Initiation Protocol (SIP) are provided. The method includes opening a port between the private network and a public network in a Network Address Translation (NAT) using a first SIP message, and managing a remote device located in the private network through the open port. Accordingly, a remote management server (or a manager) can collect and configure necessary information by actively accessing to a management target.