A SIP(Session Initiation Protocol) Load Balancing Apparatus and Method

The present invention provides a Session Initiation Protocol (SIP)-based load balancing apparatus and method. The apparatus receives a message transmitted from a user at a position in front of a plurality of proxy servers each connected in parallel and decodes the received message. The apparatus selectively performs addition, renewal and deletion of user information according to an expiration field of a header and transmits the decoded message to a proxy server, if the decoded message is a REGISTER message, searches for a proxy server that will handle a destination address, increases a load of the proxy server and transmits the decoded message to the proxy server, if the decoded message is a INVITE message, and examines a proxy server of the destination address and transmits the decoded message to the proxy server, if the decoded message is a BYE message.