TSN API

TSN is grouped into three basic key component categories that are required for complete real-time communication. There are multiple specifications that come under these 3 categories:

  1. Time Synchronization i.e. 802.1AS(gPTP)

  2. Scheduling and traffic shaping - i.e., 802.1Qav, 802.1Qbv, 802.1Qbu/802.3br, 802.1CB and 802.1Qci.

  3. Selection of communication paths, reservation and fault tolerance - i.e., SRP (802.1Qat) and 802.1Qcc are key standards that define the system configuration of TSN networks.

Standards Support on Orin SW + HW
802.1AS YES

802.1 Qbu + 802.3br

(egress path)

 YES

802.1 Qbv

(egress path)

 YES

802.1 Qav (CBS)

(egress path)

 YES
IEEE 802.1Qat (SRP) NO

This chapter provides sample application code for reference and documents the ioctl interface, which can be used to write customized applications to validate TSN specifications for Linux and QNX OS. Sample applications are used to configure end-to-end connection between 2 Ethernet interfaces.

Important Terms

Table 1.
Term Description
TC Traffic class value from 0 to 7
GCL Gate control list (this is reliant to 802.1Qbv specification)
RQ

Frame Preemption Residue Queue. The Rx queue number to which the residual

preemption frames must be forwarded. Preemption frames that are tagged and pass the SA/DA/VLAN filtering are routed and All other frames are treated as residual frames and are routed to the queue number mentioned in this field. The Queue-0 is used as a default queue for express frames, so this field cannot be programmed to a value 0.
APP Application
OS Operating system
DUT Target device