| 摘要 |
<p>A method, an apparatus, and a computer program product thereof for enabling an Internet extension to ring a conventional extension are disclosed. The apparatus comprises an SIP proxy and an RTP relay. The SIP proxy receives a calling request from the Internet extension, substitutes an exchange number for a conventional extension number comprised in the calling request, and transmits the substituted calling request to a gateway, so that the substituted calling request can be transmitted to a voice automatic machine via a telephone exchange. The RTP relay transmits the conventional extension number in DTMF format to the gateway. Thus, this invention enables the Internet extension to ring the conventional extension with lower hardware costs.</p> |
