Technical Report on Bridge-Local Guaranteed Latency with Strict Priority Scheduling
Please always quote using this URN: urn:nbn:de:bvb:20-opus-198310
- Bridge-local latency computation is often regarded with caution, as historic efforts with the Credit-Based Shaper (CBS) showed that CBS requires network wide information for tight bounds. Recently, new shaping mechanisms and timed gates were applied to achieve such guarantees nonetheless, but they require support for these new mechanisms in the forwarding devices. This document presents a per-hop latency bound for individual streams in a class-based network that applies the IEEE 802.1Q strict priority transmission selection algorithm. It isBridge-local latency computation is often regarded with caution, as historic efforts with the Credit-Based Shaper (CBS) showed that CBS requires network wide information for tight bounds. Recently, new shaping mechanisms and timed gates were applied to achieve such guarantees nonetheless, but they require support for these new mechanisms in the forwarding devices. This document presents a per-hop latency bound for individual streams in a class-based network that applies the IEEE 802.1Q strict priority transmission selection algorithm. It is based on self-pacing talkers and uses the accumulated latency fields during the reservation process to provide upper bounds with bridge-local information. The presented delay bound is proven mathematically and then evaluated with respect to its accuracy. It indicates the required information that must be provided for admission control, e.g., implemented by a resource reservation protocol such as IEEE 802.1Qdd. Further, it hints at potential improvements regarding new mechanisms and higher accuracy given more information.…
Author: | Alexej Grigorjew, Florian Metzger, Tobias Hoßfeld, Johannes Specht, Franz-Josef Götz, Jürgen Schmitt, Feng Chen |
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URN: | urn:nbn:de:bvb:20-opus-198310 |
Document Type: | Report |
Faculties: | Fakultät für Mathematik und Informatik / Institut für Informatik |
Language: | English |
Year of Completion: | 2020 |
Sonstige beteiligte Institutionen: | Siemens AG |
Dewey Decimal Classification: | 0 Informatik, Informationswissenschaft, allgemeine Werke / 00 Informatik, Wissen, Systeme / 000 Informatik, Informationswissenschaft, allgemeine Werke |
GND Keyword: | Echtzeit; Rechnernetz; Latenz; Ethernet |
Tag: | Formal analysis; Latency Bound |
CCS-Classification: | G. Mathematics of Computing / G.0 GENERAL |
Release Date: | 2020/01/22 |
Licence (German): | CC BY-SA: Creative-Commons-Lizenz: Namensnennung, Weitergabe unter gleichen Bedingungen 4.0 International |