header image for OONI-Research Reports

OONI-Research Reports

Open Culture Foundation (OCF), as a partner of the OONI community, supports censorship measurement from a local perspective and shares internet censorship findings with the public.


The Open Culture Foundation (OCF) began reorganizing the OONI project in October 2023 and opened the ooni-research project on the foundation's Github page. The project's planning details, research directions, data extraction programs, etc., are presented in an open-source and open spirit manner!

OONI Observation Data and Internet Autonomous System (ASN) Coverage." OONI primarily collects detection data of local networks through volunteers and participants to observe whether there are instances of significant interference with the internet. OONI is a project under the Tor Project, and from its inception in 2012 to 2023, it has observed data from nearly 2 billion sets, covering 241 countries, with observations across 30,000 networks.

And we are also curious about the current status and patterns of observation data in Taiwan (TW). How much observation data comes from known Autonomous System Numbers (ASNs)? Are there still Internet regions that we are unaware of and remain unobserved? Ultimately, we want to examine the data to question whether our internet is truly free.

With these questions in mind, we begin to plan and analyze OONI observation data. After the OONI detection application is executed, the observation data is uploaded to AWS S3 storage (Registry of Open Data on AWS). Therefore, it is possible to download the raw observation data through existing package tools for organization and analysis. For detailed file download procedures, please refer to the 'ooni.py' in the project folder.

Observation Data

Data fetched from September 1, 2023, to December 3, 2023, spanning a total of 94 days, with approximately over two million observation records. The minimum time interval for data is hourly. Currently, there is a data contribution for every hour, achieving a 100% coverage rate for hourly observation data.

Observation Data for Each Month
Month Days Hours
2023/09 30 720
2023/10 31 744
2023/11 30 720
2023/12/01 ~ 2023/12/03 3 120
Total 94 2,304

The total observation hours are counted on the basis of ASN (Autonomous System Number), with unique ASN in each hourly record. The data count represents the number of observations checking websites. The average observation count is calculated as the data count divided by the total observation hours. (For data organization, refer to the provided reference.)

Observation Hours
Month Total Observation Hours Data Count Average Observation Count
2023/09 2,342 712,724 304.32
2023/10 2,512 1,029,845 409.97
2023/11 2,243 945,011 421.32
2023/12/01 ~ 2023/12/03 240 90,509 377.12
Total 7337 2,778,089 378.64

ASN Data Patterns

From the observation data collected from September 2023 to December 3, 2023, there are a total of 32 unique ASNs. Among them, AS3462 and AS18041 contribute approximately 78.94% of the observation data. (For data organization, refer to the provided reference.)

ASNs with Records Each Month from September 2023 to December 3, 2023
(Sorted by Observation Data Quantity, More to Less)
ASN 2023/09 2023/10 2023/11 2023/12/01
AS3462 328,656 470,142 468,767 42,663 1,310,228
AS18041 41,567 415,974 386,789 38,415 882,745
AS18419 72,405 74,721 62,593 7,195 216,914
AS38136 2,900 3,100 3,000 300 9,300
AS1659 3,100 1,001 4,053 300 8,454
AS945 400 3,100 3,000 300 6,800
AS24158 1,511 1,520 627 598 4,256
(Excluding other ASNs without observation data each month.)
2023/09 2023/10 2023/11 2023/12/01
Total (with records each month) 450,539 969,558 928,829 89,771 2,438,697
Total (Others) 262,185 60,287 16,172 738 339,392
Total 712,724 1,029,845 945,011 90,509 2,778,089

Complete List of ASNs with Observation Data

Unique ASN
Month Unique ASN
2023/09 20
2023/10 22
2023/11 19
2023/12/01 ~ 2023/12/03 10
2023/09 ~ 2023/12/03 32

In the current registration of ASNs in Taiwan, there are a total of 437, and the observation data (TW) with unique ASNs for only 7.32%, which is a relatively low proportion.

Unique ASNs
AS945** AS9678 AS18182 AS38136** AS131668
AS1659** AS9916 AS18412 AS38841 AS134823
AS3462** AS9919 AS18419** AS38844 AS147049
AS4780 AS9924 AS19527 AS41378 AS396982
AS7539 AS17421 AS24157 AS55720
AS9416 AS17716 AS24158** AS131596
AS9674 AS18041** AS24164 AS131627
  • ** Indicating that there is a contribution of observation data throughout the period from September 2023 to December 3, 2023.
  • Period: 2023/09/01 ~ 2023/12/03


In the OONI Explorer database, Taiwan's observation data ranks among the top 10; however, an analysis of the data content reveals that approximately 80% of the current observation data is concentrated in the contributions from AS3462 and AS18041. During the analysis period, ASNs contributing data each month represent only 7.32% of the known ASNs registered in Taiwan.

At this moment, the observation data is not comprehensive and diverse enough to fully reflect the current network patterns in Taiwan, including those of the three major telecom operators, broadband services from cable TV, fixed network services, and second-class telecom services (virtual mobile network services), etc.

As one of the OONI community partners, the Open Culture Foundation is responsible for local promotion and observation. In the upcoming promotion strategy, efforts will be adjusted to assist contributors in understanding ASNs and discovering observations from unknown ASNs. Continuous provision of straightforward installation guides will also be maintained.


Continuously follow our network intervention observations.

If you are interested in OONI network intervention observations, you can refer to the project page or subscribe to the ooni-research mailing list. Relevant research information will be disseminated through this email. Refer to more observation reports.