Patent ID: 7154883

Claim:
A call setup procedure method in an Internet telephone system having an IP telephone, a VoIP gateway accommodating said IP telephone, a gate keeper for performing address resolution and a media gateway on the destination side, wherein said VoIP gateway responds to a call originated from said IP telephone to transmit an admission request (ARQ) to said gate keeper, wherein said gate keeper responds to reception of said admission request to transmit to said VoIP gateway and said media gateway an admissions confirm (ACF) after attaching an authentication key created by said gate keeper, wherein said VoIP gateway extracts the authentication key from said transmitted admissions confirm and transmits to said media gateway a call setup signal after attaching the extracted authentication key, and wherein said media gateway decides whether the authentication key attached to the admissions confirm received from said gate keeper coincides with the authentication key attached to the call setup signal of said VoIP gateway.