The Internet Observatory studies the Internet-wide adoption and usage of (new) Internet protocols by utilizing large-scale measurements. Such measurements are necessary since the Internet as one of the complexest systems ever built is not fully understood. We utilize the obtained finding to ultimately improve the performance and security of the Internet. It is operated by the Distributed Systems Group at the University of Kassel.

Approach: The observatory probes i) the entire IPv4 address space and ii) more than 50% of the domain name space to obtain a uninque perspective on the Internet-wide deployment of protocols. We currently study the following protocols:

Example study: We are currently studying the adoption of the Certificate Authority Authorization (CAA) DNS record, whose adherence by Certificate Authorities has been made mandatory in September 2017 to improve the security of the HTTPS infrastructure. Our study has revealed several security flaws in the current realization and we have been working with Internet organizations to fix them. Further details: caastudy.github.io

Example study 2: We measure the adoption of HTTP2 since September 2016. As an example outcome, our studies have identified detrimental usages of the HTTP2 Server Push features that can impact the end-user experience (e.g., make the site to appear to load slower than via HTTP1). We are currently working on mechanisms for improved push usage and bring our results into Internet standardization. Further details: http2.netray.io.

Data sets and collaboration: We pushlish our data as far as possible (data sets are listed each measurement project site individually). If you (are a researcher and) would like to collaborate, please contact us.


Oliver Hohlfeld (PI)


For any questions or concerns regarding netray.io, please contact info A T netray.io

If you are an operator and think that our measurement is impacting your infrastructure, please go to our operators page to read more about our generated traffic and how to block it.

Distributed Systems Group
Department of Electrical Engineering and Computer Science
Wilhelmshöher Allee 73
34121 Kassel