Abstract: A method for DTMF transmission between different address systems in a communication system containing a first network (NW) 20A including an SIP terminal 41A connected to an SIP server 30A, a second network (NW) 20B including an SIP terminal 41B connected to an SIP server 30B, and an SIP converter 10 connecting the first and the second NWs. When the SIP converter 10 detects coded DTMF information from one of the NWs while a session is established between the SIP terminal 41A and the SIP terminal 41B, the SIP converter 10 determines whether the other of the NWs supports the coded DTMF information. If the other of the NWs does not support the coded DTMF information, the SIP converter 10 stores voice-data DTMF corresponding to the coded DTMF information into a payload of RTP and transfers the information to the SIP terminal of the other network.

Abstract: A television phone adapter which permits an ordinary analog telephone to switch between being a telephone with a video function and a telephone without a video function. The television phone adapter includes a telephone adapter unit that detects dial operation of an analog telephone connected to a router with an IP telephone function, a video adapter unit that connects and disconnects a video connection using an IP network, sends a video taken by a camera to a communication partner and outputs a video received from the communication partner to a display 4 through the video connection in the connected state. A translation table stores correspondence between dial operation and a setting content.

Abstract: A method for DTMF transmission between different address systems in a communication system containing a first network (NW) 20A including an SIP terminal 41A connected to an SIP server 30A, a second network (NW) 20B including an SIP terminal 41B connected to an SIP server 30B, and an SIP converter 10 connecting the first and the second NWs. When the SIP converter 10 detects coded DTMF information from one of the NWs while a session is established between the SIP terminal 41A and the SIP terminal 41B, the SIP converter 10 determines whether the other of the NWs supports the coded DTMF information. If the other of the NWs does not support the coded DTMF information, the SIP converter 10 stores voice-data DTMF corresponding to the coded DTMF information into a payload of RTP and transfers the information to the SIP terminal of the other network.

Abstract: A television phone adapter in which an ordinary analog telephone can switch a telephone with a video function and a telephone without a video function.