Colt futureproofs Voice portfolio in Japan, with launch of VoiceLINE(v)

Colt is bringing its IP-based ISDN Phone Service to Japan, enabling enterprises to simplify the migration to SIP Trunking.

Tokyo, 28 April 2021Colt Technology Services has today announced an expansion of its VoiceLINE(v) service to Japan, making this offering now available in 14 countries globally.

Colt VoiceLINE(v) delivers direct ISDN to a customer’s TDM-based PBX alongside enhanced geographic coverage via Next Generation IP technology, utilising SIP Trunking to be delivered over a variety of IP-based access points. VoiceLINE(v) will replace Colt’s existing VoiceLINE ISDN, with customers now being able to continue to use their TDM or hybrid IP-TDM PBX.

For more than 20 years, Colt has offered high-quality voice services underpinned by the most comprehensive network, with its ISDN and SIP interfaced voice offering serving thousands of customers throughout Europe and Japan. With the launch of VoiceLINE (v) in Japan, customers can now benefit from traditional ISDN infrastructure with modern SIP trunking delivered over the Colt IQ Network – ensuring they are able to meet the challenging demands of the modern workplace.

Masato Hoshino, Colt Technology Services President and Head of Asia, says: “Last year, many companies around the world activated their business continuity plans, triggering dramatic growth in voice traffic. As new work styles were adopted, the demand for voice traffic among call centres, conference service providers and large enterprises continued to grow. We are proud to support our customers with market-leading voice services that can be delivered under any circumstances.

“We are excited to expand our VoiceLINE(v) into Japan, putting us in the best possible position to support our customers’ business objectives in Asia.”

While delivering ISDN services over SIP, Colt provides the opportunity to transition easily, from both a commercial and technical perspective, to SIP Trunking whenever enterprises are ready. Delivering a futureproofed VoIP-based ISDN telephony service, which offers more features than traditional TDM voice, allows enterprises to continue using their current PBX and telephone devices without having to invest in their own IP network. This gives enterprises flexibility in planning the evolution of their IP and voice infrastructure and prepare for a simple transition to cloud-based telephony or pure SIP Trunking.

In addition to Japan, Colt’s VoiceLINE(v) is  already available in 13 European countries. They are Austria, Belgium, Denmark, France, Germany, Ireland, Italy, Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. With this, Colt can offer similar services to global players across the world.

Colt’s VoiceLINE (v) is available in Japan from April 1st.


About Colt

Colt strives to transform the way the world works through the power of connectivity – taking what’s always been in its DNA to enable customers’ success. The Colt IQ Network connects more than 900+ data centres and over 29,000 on net buildings across Europe, Asia and North America’s largest business hubs.

Colt understands today’s shifting connectivity requirements and provides agile, on-demand and secure high bandwidth networking and voice solutions to ensure enterprises can thrive. Customers include data-intensive organisations spanning over 210 cities in more than 30 countries. Colt is a recognised innovator and pioneer in Software Defined Networks (SDN) and Network Function Virtualisation (NFV). Privately owned, Colt is one of the most financially sound companies in the sector, and because of this, it’s able to put its customers’ needs at its core. For more information, please visit

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