Patent ID: 8102873

Claim:
A communication system comprising: a plurality of terminal accommodation apparatuses to accommodate terminal apparatuses, respectively; a communication apparatus connected to an IP (Internet protocol) network; and digital subscriber lines to connect said plurality of terminal accommodation apparatuses and said communication apparatus; wherein each of said terminal accommodation apparatuses includes a PCM (pulse code modulation) modulator and demodulator to convert a first voice signal from said respective terminal apparatus to a first PCM data and convert a second PCM data from said communication apparatus to a second voice signal, and transmits said first PCM data to said communication apparatus using a signal having a first time division frame structure via said digital subscriber line; and said communication apparatus includes a plurality of IP conversion units, each of said IP conversion unit includes a VoIP processing unit to convert said first PCM data received from a respective said terminal accommodation apparatus to a first IP packet and convert a second IP packet received from said IP network to said second PCM data, and transmits said second PCM data to said respective terminal accommodation apparatus using a signal having a second time division frame structure via said digital subscriber line.