Injection Time Planning: Making CQF Practical in Time-Sensitive Networking

Yan, Ji; Quan, Wei; Jiang, Xuyan; Sun, Zhigang

doi:10.1109/infocom41043.2020.9155434

Cited by 88 publications

(20 citation statements)

References 21 publications

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“…Since an ST packet may be sent at any time point in the pre-planned time-slot, the deterministic accuracy achieved by CQF is consistent with a time-slot, which is generally configured to hundreds of microseconds or tens of microseconds [22], [25]. This determinism precision is unacceptable for many real-time applications that require strict transmission determinism [1].…”

Section: Challengesmentioning

confidence: 99%

Fenglin-I: An Open-Source Time-Sensitive Networking Chip Enabling Agile Customization

Quan

Yan

et al. 2023

IEEE Trans. Comput.

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Time-Sensitive Networking (TSN) technology is experiencing diverse application requirements and forming a complicated standard system. It is extremely difficult to design a one-fits-all chip for all TSN applications. Therefore, application-driven TSN chip customization is inevitable. Generally, chip customization starts from a "clean-slate". For complicated ASIC chips, that results in significant development overhead. Inspired by RISC-V chips, an open-source template will significantly reduce the customization complexity. Along this road, we propose an open-source TSN chip named Fenglin-I. Fenglin-I includes a high-level abstraction to build a relationship between application requirements and chip implementation, source code of a real chip named FastTSN to provide reference code for chip implementation, and software tools to facilitate chip verification. Based on Fenglin-I, we further propose a TSN chip customization method that provides step-by-step guidance about customizing TSN chips agilely. To verify the effectiveness of Fenglin-I and the proposed customization method, we use FPGA arrays to prototype and verify FastTSN. The results show that FastTSN achieves microsecond-level transmission jitter for unicast and multicast time-critical traffic. Additionally, we demonstrate two domain-specific TSN chip customization cases in which the customized chips reuse at least 84% of FastTSN code while meeting their requirements.

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Section: Challengesmentioning

confidence: 99%

Fenglin-I: An Open-Source Time-Sensitive Networking Chip Enabling Agile Customization

Quan

Yan

et al. 2023

IEEE Trans. Comput.

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“…2. The end-to-end determinism of flow transmission is assured with the bounded latency As analyzed in [20], unscheduled flow injection into the network is easy to cause chaotic flow confluences on the same slot. It further results in slot congestion and overflow due to excessive occupancy beyond the slot capacity.…”

Section: A Network and Flow Modelmentioning

confidence: 99%

Efficient Flow Scheduling for Industrial Time-Sensitive Networking: A Divisibility Theory-Based Method

Zhang

et al. 2022

IEEE Trans. Ind. Inf.

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Industrial Time-Sensitive Networking (TSN) provides deterministic mechanisms for real-time and reliable flow transmission. Increasing attention has been paid to efficient scheduling for time-sensitive flows with stringent requirements such as ultra-low latency and jitter. In TSN, the fine-grained traffic shaping protocol, cyclic queuing and forwarding (CQF), eliminates uncertain delay and frame loss by cyclic traffic forwarding and queuing. However, it inevitably causes high scheduling complexity. Moreover, complexity is quite sensitive to flow attributes and network scale. The problem stems in part from the lack of an attribute mining mechanism in existing frame-based scheduling. For time-critical industrial networks with large-scale complex flows, a so-called hyper-flow graph based scheduling scheme is proposed to improve the scheduling scalability in terms of schedulability, scheduling efficiency and latency & jitter. The hyper-flow graph is built by aggregating similar flow sets as hyper-flow nodes and designing a hierarchical scheduling framework. The flow attribute-sensitive scheduling information is embedded into the condensed maximal cliques, and reverse maps them precisely to congestion flow portions for rescheduling. Its parallel scheduling reduces network scale induced complexity. Further, this scheme is designed in its entirety as a comprehensive scheduling algorithm GH 2 . It improves the three criteria of scalability along a Pareto front. Extensive simulation studies demonstrate its superiority. Notably, GH 2 is verified its scheduling stability with a runtime of less than 100 ms for 1000 flows and near 1/430 of the SOTA FITS method for 2000 flows.

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“…We are the first to investigate the configuration of Multi-CQF shapers. The only works so far addressing CQF configuration are: [31], which proposes an ILP formulation for the routing and queue assignment configuration problem in CSQF, and [32], which considers that the routes are given and focuses on the assignment of streams to queues in CQF.…”

Section: A Related Workmentioning

confidence: 99%

Configuration and Evaluation of Multi-CQF Shapers in IEEE 802.1 Time-Sensitive Networking (TSN)

2022

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Time-Sensitive Networking (TSN) is a task group of the IEEE 802.1 standardization working group (WG) developing the IEEE 802.1 TSN communication standards. TSN is developing a "toolbox" of many standards to provide support for enabling the separation of critical and non-critical traffic, the timeliness and dependability, i.e., reliability, fault-tolerance, and security, of critical traffic. In this paper we focus on the Cyclic Queuing and Forwarding (CQF) traffic shapers, such as the original CQF, the Cycle Specified Queuing and Forwarding (CSQF) and an extension of those, the so-called Multi-CQF shaper. We define formally the problem of configuring CQF-based networks. We have developed a Constraint Programming (CP) formulation for Multi-CQF, as well as a Simulated Annealing (SA)-based metaheuristic solution. These solutions can also obtain results for CQF and CSQF, which can be seen as a special case of Multi-CQF. The CQF configuration problem is NP-hard. We evaluate our solutions on several test cases and scenarios. The CP formulation can find optimal solutions for small problem sizes but does not scale for realistic test cases. However, SA is able to handle large test cases and to find good quality solutions, making it suitable for both design-time and runtime network configuration. We also present comprehensive evaluation results comparing the CQF-based variants (CQF, CSQF, Multi-CQF) on industrial use cases, contrast them to the Time Aware Shaper (TAS, 802.1Qbv), and discuss their advantages and disadvantages.

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Injection Time Planning: Making CQF Practical in Time-Sensitive Networking

Cited by 88 publications

References 21 publications

Fenglin-I: An Open-Source Time-Sensitive Networking Chip Enabling Agile Customization

Fenglin-I: An Open-Source Time-Sensitive Networking Chip Enabling Agile Customization

Efficient Flow Scheduling for Industrial Time-Sensitive Networking: A Divisibility Theory-Based Method

Configuration and Evaluation of Multi-CQF Shapers in IEEE 802.1 Time-Sensitive Networking (TSN)

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