H.323 protocol-based terminal access method for packet network

The present invention provides a packet network is applied to a terminal access method based on the H.323 protocol, comprising the steps of: receiving the network call communication phase, the gatekeeper using elliptic curve digital signature system, the public key certificate of the terminal to achieve secure authentication, and generated by the Diffie-Hellman key distribution scheme shared session key, the access network to establish a secure channel; network call control communication phase, terminals and gatekeepers based on a shared session key, network access over a secure channel established symmetrical cryptographic mechanism to establish a secure channel call connection; network connection control communication phase, a call connection in a secure channel, using a symmetric cryptographic key agreement mechanisms. The method of the present invention is used for secure communication between the multimedia terminal and the access network terminal security, user authentication with fast speed in bit encryption strength.