TOKYO -- NTT Communications Corporation (NTT Com) announced today that its Arcstar Unified Communications Services will introduce the SIP Trunking Plan to allow Arcstar Global IP-VPN users to dial external lines for high-quality, low-rate voice communications worldwide beginning May 31. The service initially will be offered to customers in Singapore and then gradually expanded to cover other regions, making the plan available worldwide by March 2012. Incoming calls from external lines will be covered under the plan from April 2012 at the earliest.

The SIP Trunking Plan will reduce total cost of ownership by unifying voice and data communications over Arcstar Global IP-VPN. Operation and maintenance will also be simplified by this one-stop, end-to-end solution combining the necessary systems and hardware for voice and data, including network and devices (VoIP gateway).

Arcstar Unified Communications Services currently offer IP-based internal dialing among global offices, including within Japan, under the Extension Plan. The newly expanded Arcstar Unified Communications Services will provide globally seamless unified voice, video, web conferencing, voice messaging, presence and instant messaging for Arcstar Global IP-VPN, backed by NTT Com's extensive experience and expertise in networks, cloud computing and data centers.

To further meet growing market needs for low-cost worldwide internal/external voice-over-Internet-protocol (VoIP) services, Arcstar Unified Communications Services will add two more plans this year: the UCaaS (Unified Communications as a Service) Plan in August and the Contact Center Plan for globally seamless SaaS call-center services in December. Enterprise customers will be able to enhance the efficiency of their global communications by integrating these plans with the SIP Trunking Plan.

NTT Communications Corp. (NYSE: NTT)