Abstract: A method of initiating a V5.2 interface connection between an access device and a local exchange includes initiating the V5.2 interface connection, initiating a first timer, determining whether a variant and interface identifier (VID) message has been received within a first time period, and stopping the first timer when the VID message is received. The method further includes initiating a second timer, sending an unblock-all-ports (UBA) message to the local exchange, determining whether a feedback message of the UBA message is received from the local exchange, reinitiating the V5.2 interface connection if the feedback message of the UBA message is received, signifying that the V5.2 interface connection is initiated.

Abstract: A method for safely downloading setting data in a Voice over Internet protocol (VoIP) system including a server, a VoIP device, and a console, includes steps of: establishing communication between the console and the VoIP device; determining whether a certificate authority of the VoIP device is valid; generating a session key randomly if the certificate authority of the VoIP device is valid; encrypting the setting data of the VoIP system employing the session key; encrypting the session key employing a public key; transmitting the encrypted data and the encrypted session key to the VoIP device; decrypting the encrypted session key employing a private key after the VoIP device received the encrypted data and the encrypted session key; decrypting the encrypted data to restore the setting data employing the session key; and checking whether the setting data are correct data.