Engineering SD-WAN Routing Engine @ Open Systems

Julian Klaiber

Software & Systems Engineer • Switzerland 🇨🇭

Building high-performance routing brains, SD-WAN platforms, and cloud-native networking infrastructure with eBPF, SRv6, and Go/Rust.

Core Focus Areas & Tech Stack
Software-Defined Networking (SDN)
SRv6 & IPv6 Architecture
eBPF & XDP Data Paths
Linux Systems & Kernel Network Stack
Managed SASE & SD-WAN Routing
Go / Rust / C / Python
Cloud Native & Kubernetes
Apache Kafka & High-Throughput Pipelines
FD.io VPP Data Plane

01. Experience

Software Systems Engineer

📍 Switzerland • Apr 2024 — Present Current

Building the routing brain of a Managed SASE platform and engineering next-generation SD-WAN control planes.

  • Designing resilient, high-availability routing engines for enterprise SASE deployments.
  • Developing cloud-native control plane software to automate path selection and traffic engineering.
  • Optimizing network protocol interactions and data path telemetry.
#SD-WAN#SASE#Routing Control Plane#Go#Cloud Native#Linux

Research and Network Engineer

📍 Rapperswil, Switzerland • Oct 2021 — Mar 2024

Applied research in Software-Defined Networking (SDN) and Telecommunications, creating cloud-native applications to bridge application logic with network paths.

  • Engineered intent-driven networking architectures leveraging eBPF, XDP, and Segment Routing over IPv6 (SRv6).
  • Built high-throughput Path Tracing probe collectors integrated with Apache Kafka.
  • Developed custom VPP (Vector Packet Processing) extensions and dynamic service function chaining controllers.
#SDN#SRv6#eBPF#Kafka#VPP#Cloud Native#Telco
📍 Rapperswil, Switzerland • Mar 2019 — Sep 2021

Research in SDN with Segment Routing (SRv6) and cloud environments, building native data path automation software.

  • Implemented SRv6 service programming algorithms for service provider backbones.
  • Engineered event-triggered path calculation microservices for network service chaining.
#SRv6#SDN#Python#C#IPv6#Docker

System Operator

📍 Schaffhausen, Switzerland • Aug 2016 — Feb 2019

Built and operated enterprise private cloud infrastructure utilizing VMware and Citrix server virtualization product suites.

  • Managed hypervisor hosts, virtual networks, and storage infrastructure for enterprise customers.
  • Automated operational workflows and systems provisioning.
#VMware#Citrix#Private Cloud#SysAdmin#Networking

02. Publications & Research

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IEEE 2023
ISBN: 979-8-3503-2781-6

Optimizing Path Tracing Probe Collection for Kafka-Based Storage: Identifying and Addressing Performance Bottlenecks

Authors: Julian Klaiber, Severin Dellsperger, Prof. Laurent Metzger
Published in: 2023 International Conference on Electrical, Computer and Energy Technologies (ICECET)
Abstract & BibTeX

Efficient and accurate processing of Path Tracing probes is essential for using Path Tracing technology to analyze and diagnose service provider networks. This paper presents a modular and optimized probe collector that addresses several performance bottlenecks. The probe collector consists of three main components: collecting, processing, and publishing. The collector component captures incoming probes from physical interfaces, while the processing component inspects and formats captured packets. Finally, the publisher component ensures efficient transmission of processed packets to designated Kafka topics. Performance evaluation under heavy traffic loads demonstrates high packet processing rates with minimal loss.

BibTeX Citation
@inproceedings{klaiber2023optimizing,
  title={Optimizing Path Tracing Probe Collection for Kafka-Based Storage: Identifying and Addressing Performance Bottlenecks},
  author={Klaiber, Julian and Dellsperger, Severin and Metzger, Laurent},
  booktitle={2023 International Conference on Electrical, Computer and Energy Technologies (ICECET)},
  pages={1--7},
  year={2023},
  organization={IEEE},
  isbn={979-8-3503-2781-6}
}
IEEE 2023
ISBN: 979-8-3503-3807-2

Network-Driven Service Programming Controller using SRv6: A Demonstration

Authors: Julian Klaiber, Severin Dellsperger, Prof. Laurent Metzger
Published in: 2023 14th International Conference on Network of the Future (NoF)
Abstract & BibTeX

This demo paper presents a hands-on demonstration of a dynamic, network-driven path calculation and service function chaining solution for service provider networks. The proposed solution addresses challenges associated with static service consumption, such as complex management and inability to react to network changes. By leveraging Segment Routing over IPv6 (SRv6) capabilities, our solution enables efficient and scalable path calculations, facilitating improved network service management.

BibTeX Citation
@inproceedings{klaiber2023network,
  title={Network-Driven Service Programming Controller using SRv6: A Demonstration},
  author={Klaiber, Julian and Dellsperger, Severin and Metzger, Laurent},
  booktitle={2023 14th International Conference on Network of the Future (NoF)},
  pages={1--3},
  year={2023},
  organization={IEEE},
  isbn={979-8-3503-3807-2}
}
IEEE 2021
ISBN: 978-3-903176-36-2

Dynamic Service Programming with Path Preprocessing

Authors: Julian Klaiber, Severin Dellsperger, Prof. Laurent Metzger, Ahmed Abdelsalam, Francois Clad
Published in: 2021 17th International Conference on Network and Service Management (CNSM)
Abstract & BibTeX

Proposes a practical solution for dynamic, event-triggered, and fast path calculations that program services and permit a so-called service chain directly in service provider backbones. Based on Segment Routing over IPv6 (SRv6) functionalities, implementing the source-based routing paradigm with native IPv6 encapsulation. Employs a cloud-native development approach for elasticity, fault-tolerance, and high performance.

BibTeX Citation
@inproceedings{klaiber2021dynamic,
  title={Dynamic Service Programming with Path Preprocessing},
  author={Klaiber, Julian and Dellsperger, Severin and Metzger, Laurent and Abdelsalam, Ahmed and Clad, Francois},
  booktitle={2021 17th International Conference on Network and Service Management (CNSM)},
  pages={1--9},
  year={2021},
  organization={IEEE},
  isbn={978-3-903176-36-2}
}

03. Education

Master of Science in Computer Science

Software Defined Networking
Eastern Switzerland University of Applied Sciences (OST)
Sept 2021 — Feb 2024
Master Thesis:
"Leveraging eBPF for Intent-Driven Application-Centric End-to-End Segment Routing over IPv6"

Explores how Linux eBPF kernel hooks can be dynamically programmed to parse application intent and attach SRv6 policies directly at socket layer to achieve deterministic end-to-end traffic engineering.

Project Thesis 2: "Improving Path Tracing Probe Collection for Kafka-Based Storage: Identifying and Addressing Performance Bottlenecks"
Project Thesis 1: "Improving VPP for Path Tracing"

Bachelor of Science in Computer Science

Network and Security
Eastern Switzerland University of Applied Sciences (OST)
Sept 2017 — Aug 2021
Bachelor Thesis:
"Segment Routing Service Programming"

Designed a scalable source-routing scheme using SRv6 headers to dynamically chain virtual network functions without intermediate state.

Project Thesis: "Service Chaining Path Calculation"