Conducted demonstration experiments on ISP traffic aggregation and effect measurement aiming at efficient regional distributed network construction

~ Tried Japan's first open caching mechanism and measured effectiveness from the user's perspective ~

Cable TV Co., Ltd. (Headquarters: Tochigi City, Tochigi Prefecture, Representative Director: Mitsuhiro Takada, hereinafter Cable TV) and J-Stream Inc. (Mothers: 4308 President Toshio Ishimatsu, hereinafter J-Stream) have improved the efficiency of Internet traffic distribution. We are pleased to inform you that we will carry out the first open caching demonstration experiment * 1 in Japan.


Japan's Internet has a structural problem of "concentration of traffic exchange bases in the Tokyo and Osaka areas" due to the historical background in which telecommunications carriers and content companies have developed with geographical consolidation in the capital area. And this problem causes problems such as "communication vulnerability in times of disaster" and "communication quality gap between urban and rural areas". Furthermore, in recent years, Internet traffic in Japan has been increasing at a pace of about 20% annually, and in 2020, due to the increase in home hours to prevent the spread of new coronavirus infections, etc., about 60% compared to the previous year. An increase in degree has been confirmed.

In this demonstration experiment, "By forming a traffic exchange base in the region, collecting the traffic of local ISPs, and inviting content providers there. In order to "improve the efficiency and stability of the Internet in Japanas a whole by shifting to a regionally distributed network structure", it includes "place a shared cache (including HTTPS) in a centralized ISP in the area and measure its effect".

On the other hand, we will introduce and verify a new system called "open caching" * 2 as one of the shared caches to be placed in the centralized ISP. This verification will be the first public demonstration experiment for the system in Japan.

Demonstration experiment outline

1.Implementation location

  • Cable TV Co., Ltd. Tochigi Center (Tochigi City, Tochigi Prefecture), etc.

2.Experiment contents

  • Server installation for open caching
  • Streaming distribution by open caching
  • Effect measurement by streaming QoE

3.Experiment period

  • From November 1st to December 31st, 2021 (planned)

※1 About the demonstration experiment

This demonstration experiment will be conducted by Cable Television Co., Ltd. in the "Contract for research and study on HTTPS communication cache utilization type intensive ISP for improving traffic distribution efficiency" (procurement number: 0049-0099), which was publicly invited by the Ministry of Internal Affairs and Communications in May 2021. Has been selected as a contractor by the Ministry, and will be implemented as part of this contract work. In this demonstration experiment, cable TV / J-Stream will set the system as a CDN operator and measure the effect from the viewpoint of streaming QoE * 3.

※2 Open caching

This is a new type of cooperation model between SP and CDN providers, and is a model that uses the cache server installed by the ISP as a shared cache server for the CDN. The Streaming Video Alliance, an industry group in the United States, is promoting standardization.

※3 Streaming QoE

It is a method to measure the reception status of video streaming from the user's point of view. In the past demonstration experiments, only indicators such as distribution quality were measured, but this time we will also measure the effect from the user's perspective.
J-Stream will continue to actively verify and introduce new technologies with the aim of improving the distribution efficiency of domestic network traffic.

■About Cable TV Co., Ltd.

As a community-based broadcasting and communication media company, Cable Television Co., Ltd. contributes to the development of local culture and communities by providing high-quality, stable, and diverse services, and will continue to contribute to the lives of local customers. We will continue to provide indispensable services.

Company name (trade name) Cable TV Co., Ltd.
Established May 1987
Capital 376.45 million yen
Representative President and CEO Mitsuhiro Takada
Business content (1)Wired general broadcasting business based on the Broadcasting Law (Minister of Internal Affairs and Communications registration registration number KT0113)
(2)Telecommunications business based on the Telecommunications Business Law (Minister of Internal Affairs and Communications registration number Seki No. 14)

■About J-Stream Inc.

Since its establishment in 1997, J-Stream has continued to develop its business centered on video distribution.
In addition to video distribution utilizing our own content delivery network (CDN),J-Stream produce and operate videos, create websites, develop systems, and make profits from video advertisements by utilizing the know-how we have accumulated so far. We support the use of videos in all corporate activities by providing comprehensive services and solutions up to the support for conversion.

Company name (trade name) J-Stream Inc.
Securities code 4308(TSE Mothers)
Established May 1997
Capital 2,182.37 million yen (as of the end of June 2021)
Representative Representative Director Toshio Ishimatsu
Business content (1)Service industry that provides video data and various information in network systems
(2)Contract business related to member information management, commercial transactions, and settlement processing using a network system
(3)Planning, production, sales and leasing of digital contents and publications
(4)Planning and development, operation, production, sales, import / export / rental and agency business of hardware, software and incidental services related to network systems.
(5)Planning / production and agency business related to advertising / promotion
(6)Consulting, research, analysis, research, etc. related to 1 to 5
main office 〒105-0014 2-5-6 Shiba, Minato-ku, Tokyo Shiba 256 Square Building 6th floor
West Japan Sales Office Tel 03-5765-7000 Fax 03-5765-3520
〒530-0003 2-4-27 Dojima, Kita-ku, Osaka-shi, Osaka Shin-Fujita Building 5th floor
Tel 06-4796-6160 Fax 06-4796-6166

■Contact for media inquiries regarding this matter

Cable TV Co., Ltd. Engineering Department
Tel 0282-25-1811
Email URL:

J-Stream Inc. Management Headquarters Legal and Public Relations Department (Responsible: Tsunetomi)
Tel 03-5765-7744