Kristjon Ciko

• Welzl, Michael; Islam, Safiqul; Ciko, Kristjon; Barhaugen, Petter & Haukebøe, Oskar (2025). NETHINT: Monitoring Local Network Interference With Passive Measurements, 2025 International Conference on Computing, Networking and Communications (ICNC). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9798331520960. p. 668–674. doi: 10.1109/icnc64010.2025.10993931. Full text in Research Archive Show summary

  The "quality" of a home Internet connection is hard to quantify, as it is a subjective measure encompassing many factors. One of them, the detection of local (as opposed to remote) traffic interference, is not provided by existing tools. We address this with NETHINT, a tool to detect whether users and their applications disturb each other in a home network. NETHINT identifies traffic correlations via passive online latency monitoring. We explain the inner workings of NETHINT, and show how it can be successfully applied for live online root cause analysis of delay in a local network.

• Guibert, Loïc; Reynaud, Sébastien; Weppe, Olivier; Ciko, Kristjon; Welzl, Michael & Rumley, Sébastien (2025). TRAFFIC: Testbed foR Assessing energy eFFiciency In throughput Computing. In Palumbo, Francesca; Tumeo, Antonino; Varbanescu, Ana Lucia & Simmhan, Yogesh (Ed.), CF '25 Companion: Proceedings of the 22nd ACM International Conference on Computing Frontiers: Workshops and Special Sessions. Association for Computing Machinery (ACM). ISSN 9798400713934. p. 99–107. doi: 10.1145/3706594.3727961. Full text in Research Archive Show summary

  Information and Communication Technologies (ICT) represent a significant share of global resource usage. Notably, the energy consumption of data centres has emerged as a critical concern, escalating rapidly, especially with the rise of generative Artificial Intelligence (AI) models. This surge in energy demand calls for efforts focused on measuring and reducing the energy and carbon footprints of components used in ICT service delivery. However, the variety and multitude of devices involved in these services make it challenging to accurately measure and evaluate these footprints. In this paper, we propose an alternative approach to assess energy impacts by considering data centres for what they are: throughput computing systems offering ICT services. We define a simple experimental testbed and evaluate several machines with different hardware capacities. These machines serve two ICT services: a loop incrementing a counter until a defined limit, and an AI inference predicting the next token based on an input. Our experiment highlights three main take-aways: (a) the CPU usage is a poor predictor of the power consumption, (b) the energy or CO2 quantity associated with a service visit highly depends on the total load the service is facing, and (c) modern machines do not yield better energy figures compared to older ones in all circumstances.

• Ciko, Kristjon; Welzl, Michael & Teymoori, Peyman (2023). Going Dark: A Software "Light Switch" for Internet Servers. IEEE Workshop on Local and Metropolitan Area Networks. ISSN 1944-0367. doi: 10.1109/LANMAN58293.2023.10189419. Full text in Research Archive Show summary

  To fight global warming, carbon emissions must urgently be reduced. In this paper, we look at opportunities to do so by diminishing the operational energy usage of an important always-on element of the Internet: server systems. Our measurements from a server host indicate that there is probably not much to be gained by making a significant software change - but, depending on the system, a simple, easily overlooked configuration update may make a difference at no performance cost. This difference is small per server (in the order of an LED light bulb). Given the multitude of permanently operational servers in the world, it may however be significant at scale.

• Ciko, Kristjon; Teymoori, Peyman & Welzl, Michael (2022). LGC-ShQ: Datacenter Congestion Control with Queueless Load-Based ECN Marking. Computer communication review. ISSN 0146-4833. 52(4), p. 2–11. doi: 10.1145/3577929.3577931. Full text in Research Archive Show summary

  We present LGC-ShQ, a new ECN-based congestion control mechanism for datacenters. LGC-ShQ relies on ECN feedback from a Shadow Queue, and it uses ECN not only to decrease the rate, but it also increases the rate in relation to this signal. Real-life tests in a Linux testbed show that LGC-ShQ keeps the real queue at low levels while achieving good link utilization and fairness.

• Ciko, Kristjon; Welzl, Michael & Teymoori, Peyman (2021). PEP-DNA: A Performance Enhancing Proxy for Deploying Network Architectures. In Gunes, Mehmet & Lee, Patrick P.C. (Ed.), 2021 IEEE 29th International Conference on Network Protocols (ICNP 2021). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781665441315. doi: 10.1109/ICNP52444.2021.9651953. Full text in Research Archive
• Ciko, Kristjon (2021). Integrating IP and Future Networks through a Performance Enhancing Proxy. In Machuca, Carmen Mas; Martins, Lucia; Sargento, Susana; Wauters, Tim; Jorge, Luisa; Salhab, Nazih & Chemouil, Prosper (Ed.), 2021 12th International Conference on Network of the Future (NoF). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781665424349. doi: 10.1109/NoF52522.2021.9609870. Full text in Research Archive
• Ciko, Kristjon; Welzl, Michael & Marek, Marcel (2020). TAPS and RINA: Do they fit together? In Chatras, Bruno & Lopez, Diego (Ed.), 2020 23rd Conference on Innovation in Clouds, Internet and Networks and Workshops (ICIN). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781728151274. p. 35–40. doi: 10.1109/ICIN48450.2020.9059406. Full text in Research Archive
• Ciko, Kristjon & Welzl, Michael (2019). First Contact: Can Switching to RINA save the Internet? In Galis, Alex; Guillemin, Fabrice; Noldus, Rogier; Secci, Stefano; Filip, Idzikowski & Sayit, Müge Fesci (Ed.), 22nd Conference on Innovation in Clouds, Internet and Networks and Workshops, ICIN 2019. IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781538683361. p. 37–42. doi: 10.1109/ICIN.2019.8685912. Full text in Research Archive

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• Ciko, Kristjon; Welzl, Michael & Teymoori, Peyman (2022). Improving Internet Performance with a "Clean-Slate" Network Architecture - The Case of RINA. Universitetet i Oslo. Full text in Research Archive Show summary

  Today’s Internet is facing significant challenges as the number of the connected devices, applications, and the amount of traffic grow tremendously. The challenges are particularly related to the insufficient security and performance, complexity in providing mobility and multihoming, and the inability to easily accommodate new protocols and technologies. Over the last two decades, there has been considerable effort by the networking research community to evolve or redesign the Internet architecture. Unlike evolutionary approaches, “clean-slate” designs follow a more drastic path to overcome the fundamental architecture limitations of the current Internet. However, such solutions are facing large deployment barriers, mainly because the Internet does not provide architectural modularity. Among the “clean-slate” initiatives, RINA—the Recursive InterNetwork Architecture—is perhaps the most drastic one which attempts to offer a general solution with a complete networking theory. In addition, the recursive nature of RINA introduces potential benefits in many aspects of networking such as management, routing, security, and congestion control. This dissertation tackles the deployment challenges and investigates several strategies to deploy a new clean-slate architecture such as RINA in the current networks. These strategies are: (1) direct usage with a fall-back, (2) adapting the Application Programming Interface (API), and (3) a gateway to translate between protocols. Real-life experiments of the first congestion control approach that is suitable for a flexible recursive architecture show the performance improvement that can be attained with these strategies.

• Ciko, Kristjon; Welzl, Michael & Teymoori, Peyman (2021). PEP-DNA: a Performance Enhancing Proxy for Deploying Network Architectures. Universitetet i Oslo. ISSN 9788273686008. Full text in Research Archive Show summary

  Deploying a new network architecture in the Internet requires changing some, but not necessarily all elements between communicating applications. One way to achieve gradual deployment is a proxy or gateway which “translates” between the new architecture and TCP/IP. We present such a proxy, called “Performance Enhancing Proxy for Deploying Network Architectures (PEP-DNA)”, which allows TCP/IP applications to benefit from advanced features of a new network architecture without having to be redeveloped. Our proxy is a kernel-based Linux implementation which can be installed wherever a translation needs to occur between a new architecture and TCP/IP domains. We discuss the proxy operation in detail and evaluate its efficiency and performance in a local testbed, demonstrating that it achieves high throughput with low additional latency and low CPU and memory overhead. In our experiments we use the Recursive InterNetwork Architecture (RINA) and Information- Centric Networking (ICN) as examples, but our proxy is modular and flexible, and hence enables realistic gradual deployment of any new “clean-slate” approaches.

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