arXiv subjects

Moritz Flüchter

Publications and source records attributed to Moritz Flüchter.

5 recordsLinked to original sources

arXiv2026

Performance Evaluation of Selection Strategies for Inter-Satellite Paths in Walker-Delta Constellations

In LEO satellite constellations, traffic between a user terminal and a gateway is carried over a satellite path. As the satellite constellation rotates around Earth, a new path must be reselected repeatedly from a set of path candidates. In this paper, we study the impact of path selection strategies on several metrics: path length in terms of Euclidean distance and hop count, path-change rate, and rate of used links. These metrics are relevant because they affect either communication latency or the complexity of control and resource management. We explain how path candidates are generated, define three heuristic path selection strategies, and evaluate them over a large set of UT-GW scenarios within a single shell of a Walker-Delta constellation with 1,156 satellites. Overall, the results show that path selection has a significant impact on both latency-related metrics and path churn.

cs.NI↗

arXiv2026

P4-TAS: P4-Based Time-Aware Shaper for Time-Sensitive Networking

Time-sensitive networking (TSN) is a set of IEEE standards that extends Ethernet with real-time capabilities. Among its mechanisms, the time-aware shaper (TAS) periodically opens and closes egress queues to protect scheduled traffic from lower-priority flows, ensuring low latency and bounded delay. Deterministic networking (DetNet), standardized by the IETF, provides similar guarantees at Layer 3 and can leverage TSN mechanisms such as the TAS. Commercially available TSN-capable switches implement TAS in hardware but rarely disclose internal delays in the TAS mechanism itself. Such delays directly affect scheduling precision, yet information about them is largely unavailable to system designers. In this work, we present P4-TAS, a P4-based implementation of the TAS on the Intel Tofino 2 switching ASIC that additionally supports per-stream filtering and policing (PSFP) and PTP time synchronization. First, we design a novel mechanism for periodic queue control that uses a continuous stream of internally generated control frames for time-triggered queue state updates. To the best of our knowledge, this enables TAS on a P4-programmable ASIC for the first time. P4-TAS additionally provides an MPLS/TSN translation layer that enables TSN time-based shaping to be applied at the boundary between TSN and DetNet domains, supporting line rates up to 400 Gb/s per port. Second, we identify and quantify three sources of internal delay that affect the precision of TAS gate transitions, providing transparency that enables more accurate TAS configuration. Our evaluation demonstrates a worst-case accumulated internal delay of 86 ns between time slices, which is well below values reported for commercial switches. Third, we propose a measurement methodology to externally measure TAS time slice accuracy, and introduce gate switching intervals (GSIs) to mitigate overlap between consecutive time slices.

cs.NI↗

arXiv2025

Rust Barefoot Runtime (RBFRT): Fast Runtime Control for the Intel Tofino

Data plane programming enables the programmability of network devices with domain-specific programming languages, like P4. One commonly used P4-programmable hardware target is the Intel Tofino switching ASIC. The runtime behavior of an implemented P4 program on Tofino can be configured with shell scripts or a Python library from Barefoot provided with the Tofino. Both are limited in their capabilities and usability. This paper introduces the Rust Barefoot Runtime (RBFRT), a Rust-based control plane library. The RBFRT provides a fast and memory-safe interface to configure the Intel Tofino. We showed that the RBFRT achieves a higher insertion rate for MAT entries and has a shorter response time compared to the Python library.

cs.NI↗

arXiv2024

Extensions to BIER Tree Engineering (BIER-TE) for Large Multicast Domains and 1:1 Protection: Concept, Implementation and Performance

Bit Index Explicit Replication (BIER) has been proposed by the IETF as a stateless multicast transport technology. BIER adds a BIER header containing a bitstring indicating receivers of an IP multicast (IPMC) packet within a BIER domain. BIER-TE extends BIER with tree engineering capabilities, i.e., the bitstring indicates both receivers as well as links over which the packet is transmitted. As the bitstring is of limited size, e.g., 256 bits, only that number of receivers can be addressed within a BIER packet. To scale BIER to larger networks, the receivers of a BIER domain have been assigned to subsets that can be addressed by a bitstring with a subset ID. This approach is even compliant with fast reroute (FRR) mechanisms for BIER. In this work we tackle the challenge of scaling BIER-TE to large networks as the subset mechanism of BIER is not sufficient for that purpose. A major challenge is the support of a protection mechanism in this context. We describe how existing networking concepts like tunneling, egress protection and BIER-TE-FRR can be combined to achieve the goal. Then, we implement the relevant BIER-TE components on the P4-programmable Tofino ASIC which builds upon an existing implementation for BIER. Finally, we consider the forwarding performance of the prototype and explain how weaknesses can be improved from remedies that are well-known for BIER implementations.

cs.NI↗

arXiv2024

Autonomous Integration of TSN-unaware Applications with QoS Requirements in TSN Networks

Modern industrial networks transport both best-effort and real-time traffic. Time-Sensitive Networking (TSN) was introduced by the IEEE TSN Task Group as an enhancement to Ethernet to provide high quality of service (QoS) for real-time traffic. In a TSN network, applications signal their QoS requirements to the network before transmitting data. The network then allocates resources to meet these requirements. However, TSN-unaware applications can neither perform this registration process nor profit from TSN's QoS benefits. The contributions of this paper are twofold. First, we introduce a novel network architecture in which an additional device autonomously signals the QoS requirements of TSN-unaware applications to the network. Second, we propose a processing method to detect real-time streams in a network and extract the necessary information for the TSN stream signaling. It leverages a Deep Recurrent Neural Network (DRNN) to detect periodic traffic, extracts an accurate traffic description, and uses traffic classification to determine the source application. As a result, our proposal allows TSN-unaware applications to benefit from TSNs QoS guarantees. Our evaluations underline the effectiveness of the proposed architecture and processing method.

cs.NI↗