| Masami Mineo | VoIP Solution Dept., IT Solution Center, |
| Atsushi Niimura | IP Solution Dept., IT Solution Center, |
| Haruyasu Ooboshi | VoIP Solution Dept., IT Solution Center, |
| Masaaki Tanaka | VoIP Solution Dept., IT Solution Center, |
The current trend toward the use of broadband networks through access services using xDSL (digital subscriber line), FTTH (fiber to the home), and CATV (cable TV) lines involves the widerspread availability of an “always-on” connection environment. As telecommunication service providers are beginning to provide IP (Internet protocol) telephony services using these network infrastructures, the Japanese Ministry of Public Management, Home Affairs, Posts and Telecommunications is developing a telephone-number plan for IP telephones to help establish an environment for the widespread use of IP telephony services. Targeting these markets, we have developed elemental technologies including: 1) communication protocol stacks, H.323 and SIP (session initiation protocol), 2) jitter control, which is a key technology for voice-over-packet transfer, 3) a real-time video communication technology, and 4) DSP (digital signal processor) middleware for telephony. We have applied these technologies to IP video phone software for PCs (personal computers), and developed a prototype of a “residential gateway” that can be connected to existing telephones to provide IP telephony services. We have been working on these elemental technologies to establish IP telephony terminal solutions in order to develop embedded IP telephone-related systems. Also, to enable the use of IPv6 (Internet protocol version 6) in the future, we have developed a prototype IPv6 version of the residential gateway that operates in the IPv6 environment.
IP Telephony, VoIP, H.323, SIP, IPv6
