7 research outputs found
Time Sensitive Networking Protocol Implementation for Linux End Equipment
By bringing industrial-grade robustness and reliability to Ethernet, Time Sensitive Networking (TSN) offers an IEEE standard communication technology that enables interoperability between standard-conformant industrial devices from any vendor. It also eliminates the need for physical separation of critical and non-critical communication networks, which allows a direct exchange of data between operation centers and companies, a concept at the heart of the Industrial Internet of Things (IIoT). This article describes creating an end-to-end TSN network using specialized PCI Express (PCIe) cards and two final Linux endpoints. For this purpose, the two primary standards of TSN, IEEE 802.1AS (regarding clock synchronization), and IEEE 802.1Qbv (regarding time scheduled traffic) have been implemented in Linux equipment as well as a configuration and monitoring system.This work has been supported by the Ministerio de Economía y Competitividad of Spain
within the project TEC2017-84011-R and FEDER funds as well as by the Department of Education
of the Basque Government within the fund for research groups of the Basque university system
IT978-16
P4-PSFP: P4-Based Per-Stream Filtering and Policing for Time-Sensitive Networking
Time-Sensitive Networking (TSN) extends Ethernet to enable real-time
communication, including the Credit-Based Shaper (CBS) for prioritized
scheduling and the Time-Aware Shaper (TAS) for scheduled traffic. Generally,
TSN requires streams to be explicitly admitted before being transmitted. To
ensure that admitted traffic conforms with the traffic descriptors indicated
for admission control, Per-Stream Filtering and Policing (PSFP) has been
defined. For credit-based metering, well-known token bucket policers are
applied. However, time-based metering requires time-dependent switch behavior
and time synchronization with sub-microsecond precision. While TSN-capable
switches support various TSN traffic shaping mechanisms, a full implementation
of PSFP is still not available. To bridge this gap, we present a P4-based
implementation of PSFP on a 100 Gb/s per port hardware switch. We explain the
most interesting aspects of the PSFP implementation whose code is available on
GitHub. We demonstrate credit-based and time-based policing and synchronization
capabilities to validate the functionality and effectiveness of P4-PSFP. The
implementation scales up to 35840 streams depending on the stream
identification method. P4-PSFP can be used in practice as long as appropriate
TSN switches lack this function. Moreover, its implementation may be helpful
for other P4-based hardware implementations that require time synchronization