Denphone | The Voice, Video & Network Specialists

Voice and Telecom Outsourcing Service

Denphone provides telephony and network support services to end clients and to third party vendors looking to sub-contract or outsource this specialized work. This enables our clients to more effectively balance costs and human resource requirements. Whether you are looking for a long term appointment to manage your phone system and IT needs, or skilled engineers to help you with the roll-out of a new system, Denphone can meet your needs.

Denphone has skilled, bilingual engineers with experience in the following technologies:

IP Telephony

Installing, configuring and maintaining desk based office phone systems is Denphone's core competence. We have a solid body of experience installing IP based phone systems for both foreign capital and Japanese national companies throughout Japan. This includes a wide range of turn-key solutions that meet the needs of clients operating in the Japanese marketplace. We also help companies cut costs by connecting remote offices over the internet - allowing offices in different countries to function as if on the same local phone system.

You can read about more of the IP telephony related work Denphone has successfully completed in the case studies. Featured IP telephony case studies include: Case Study 12: United Nations University, Case Study 10: EVision, and Case Study 4: MergerMarkets.

Networking infrastructure

Unlike traditional analog PBX systems, Voice over IP phone systems are very much an active part of a companies network infrastructure, and that has lead to us gaining a deep understanding of the workings of Voice over IP in modern network settings. We work with routers and switches from leading vendors such as Cisco, Yamaha and Dell to ensure maintenance of high quality service within our clients voice networks. Our partnership with Colt also allows us to offer a wide range of WAN/MAN solutions to best fit our clients needs.

LAN cabling

Our recommended Voice over IP solution includes separate LAN cabling for voice networks. Although daisy chaining phones is possible, we have found that separate cabling (combined with separate VLAN's) allows our customers to enjoy higher levels of voice quality and phone system stability. For smaller systems (under 30 users) we carry out cabling in house, while for larger systems we outsource cabling to one of Tokyo's leading network cabling companies.

Linux administration

Our key PBX system runs on the Centos operating system, and having worked with that for a number of years we have also built up key skills in administrating Linux based systems. Our staff have, on average, over 10 years Linux experience.

SQL databases (Sybase, SQL Server, Postgres, MySQL)

The Denphone PBX uses the Postgres database for call logging, call charge accounting and a number of other features making Postgres our database of choice. That said we have integrated turn-key solutions to work with a wide range of both commercial and open source database as per our clients requirements.

Project Management

We have skilled and experienced Project managers who have been working in Japan for many years, and who know the ins and outs of executing projects on time and under budget within the Japanese marketplace. This included experience managing local contractors as well as negotiating the best deals with local vendors.

We have experience working with the following vendor products:

Digium and Asterisk

Denphone is a Registered Digium Reseller and is proud to provide Digium and Asterisk based solutions to companies operating in Tokyo and throughout the Japanese market. Click here to read more about: Digium, Asterisk and Denphone in Japan.

Cisco Systems

Denphone is a Registered Cisco Reseller, and has Cisco certified staff able to help meet your Cisco networking and IP telephony needs. Read more about Denphone and Cisco in Japan.


Denphone is proud to be Poly (formerly Polycom) Certified Reseller. Poly manufacture an exceptional range of desk phones and conference room spider phones, as well as offering an impressive range of video conferencing solutions. Read more about Poly and Denphone.


Denphone supports a range of Ericsson PBX and handset equipment. Our core competence with Ericsson equipment is with the MX-ONE IP PBX. Featured case study: NEC Schott.


Denphone supports a number of Mitel systems in various locations throughout Japan. We provide "hand and eye" support subcontracting services as well as maintaining systems such as Robert Walters Mitel PBX systems in Tokyo and Osaka. For more information, please refer to our featured Mitel case study: Robert Walters.


Yamaha are well known for a large portfolio of products including routers. In house we use a selection of RTX1100 and RTX1200 routers and we highly recommend Yamaha routers as an inexpensive alternative to other manufacturers while still being highly reliable. We support the full range of Yamaha routing equipment.

If you are looking for a reliable partner in Japan to assist in installing or supporting the technologies and products listed above please contact us.

Please email Denphone, or telephone us at 81-3-4550-1405 for more information and prices.



Tel: +81-3-4550-1405 (Tokyo)

Tel: +81-6-4560-3200 (Osaka)

Fax: +81-3-6234-9666

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