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University of Helsinki Department of Computer Science

Department of Computer Science

Samu Varjonen


  • Postdoctoral researcher
  • Office: D228, Exactum, Kumpula

I received my Ph.D (2012) degree in Computer Science from the University of Helsinki, Finland. At the present I am working as a postdoctoral researcher in the University of Helsinki focusing on Internet of Things and related matters. I have been active in the IETF standardization work of Host Identity Protocol. I was an adjunct member of Future Internet Graduate School (FIGS 2010-2012).


I teach on courses such as Internet of Things: Exactum Greenhouse, Linux Fundamentals, and Overlay and P2P Networks.


In the current Internet the Internet Protocol address is burdened with two roles. It serves as the identifier and the locator for the host. As the host moves its identity changes with its locator. The research community thinks that the Future Internet will include identifier-locator split in some form. Identifier-locator split is seen as the solution to multiple problems. However, identifier-locator split introduces multiple new problems to the Internet. In my dissertation we concentrate on: the feasibility of using identifier-locator split with legacy application, securing the resolution steps, using the persistent identity for access control, improving mobility in multi-family environments and so improving the disruption tolerance for connectivity.

Other interests include IoT, programming, security in general, overlays, torrent, HIP, DHTs, Ethernet monitoring, Y.1731, 802.1ag and certificates.


Information on the publications can be found from the university's TUHAT-portal. Some of the older Internet drafts I have co-authored or have been otherwise involved in that are not in the TUHAT-portal: HIP Services, HIP and User Authentication, HIP OpenDHT Interface (got a RFC number 6537), HIP SRP.

Open Source

I used to use my time with HIP for Linux (HIPL).

I wrote an Open Source implementation of the ITU-T Y.1731 OAM protocol for Linux but at the moment I have no time to fix or maintain this. The Service Level Agreements formally define the acceptable limits for the operation of a network. However, the networks are getting more complex and the operators need better tools to monitor their networks, in order to avoid breeches of the Service Level Agreement. The Ethernet community has devised operation and administrations protocols for the task. However, the implementations of these protocols are based on closed source and need specialized equipment. I wrote an open source implementation of the Y.1731 protocol that runs on general purpose hardware, running a vanilla Linux distribution. The implementation allows flexibility for the developers to test out new features. Moreover, the implementation increases the number of different kinds of equipment that can be used as maintenance end points in the monitored networks.

I have also contributed HIP dissectors to Wireshark, Tcpdump, and bug fixes to BitTornado.