NTT Communications provides an overview of their IPv6 services and deployment: - They launched a pre-commercial IPv6 service in 2003 with limited dual-stack routers and tunnels across their backbone. This allowed them to gain experience and prepare for commercial launch. - Their commercial IPv6 service launched in late 2003 included native IPv6, manual tunnels, and dual-stack options. Since then they have added features but still have gaps in statistics monitoring and firewall/load balancing support. - Their dual-stack backbone has performed well but operational challenges remain in measuring performance and supporting some applications. Widespread IPv6 adoption will depend on addressing depletion and the rise of applications requiring more addresses.