1. Purpose
TSN stands for Time-Sensitive Networking, which is a set of standards developed by the IEEE (Institute of Electrical and Electronics Engineers) to provide deterministic and low-latency communication over Ethernet networks. TSN is designed to support real-time applications such as industrial automation, automotive, and audio/video streaming.
TSN achieves deterministic communication by providing time synchronization across all devices in the network, and by using traffic shaping and scheduling mechanisms to prioritize and allocate network resources for time-critical traffic. TSN also supports redundancy and fault tolerance mechanisms to ensure high availability and reliability.
Some of the key features of TSN include:
- Time synchronization: TSN uses the Precision Time Protocol (PTP) to synchronize the clocks of all devices in the network with sub-microsecond accuracy.
- IEEE 802.1AS-Rev
- Traffic shaping and scheduling: TSN uses Quality of Service (QoS) mechanisms to prioritize and allocate network resources for time-critical traffic, and to prevent congestion and packet loss.
- IEEE 802.1Qav
- IEEE 802.1Qbv
- Interoperability: TSN is designed to be compatible with existing Ethernet networks, and to support interoperability between different vendors and devices.
Overall, TSN provides a standardized and reliable solution for real-time communication over Ethernet networks, which can help to enable new applications and use cases in various industries.
The choice between 802.1Qav and 802.1Qbv depends on the specific requirements of the application. 802.1Qav is typically used in applications where bandwidth requirements are variable and unpredictable, while 802.1Qbv is typically used in applications where bandwidth requirements are fixed and predictable.
2. IEEE 802.1AS-Rev or gPTP synchronization
PTP is a protocol that enables the synchronization of clocks in a network. It uses a grandmaster architecture, where one device acts as the Grandmaster clock and the other devices act as ordinary clocks. The Grandmaster clock sends synchronization messages to the ordinary clocks, which adjust their clocks to match the Grandmaster clock.
Please see examples based on the following use cases:
- [How to configure TSN 802-1AS-Rev for TSN Endpoint]
- [How to configure TSN 802-1AS-Rev for TSN Switch]
3. IEEE 802.1Qav
In IEEE 802.1Qav or CBS (Credit-Based Shaper), each device is assigned a credit value that determines the amount of data it can transmit. The credit value is based on the bandwidth requirements of the device and the available bandwidth in the network. Devices with higher bandwidth requirements are assigned more credits, while devices with lower bandwidth requirements are assigned fewer credits.
As data is transmitted across the network, the credit values are decremented. When a device runs out of credits, it can no longer transmit data until it receives more credits. This ensures that time-critical traffic is given priority over other traffic, as devices with higher bandwidth requirements are able to transmit more data.
Please see examples based on the following use cases:
4. IEEE 802.1Qbv
802.1Qbv (Time-Aware Shaper) is a traffic scheduling technique that uses time-based scheduling to ensure that time-critical traffic is given priority over other traffic. It assigns time slots to each device based on its priority level.
Please see examples based on the following use cases:
5. References