With the transition from AVB to TSN, the number of mechanisms defined by the IEEE 802.1 TSN TG and the scope of them has greatly increased. Thus, the so called TSN standards, are often referred to as a toolbox in which each of the mechanisms is a different tool, with its own purpose and functionality. We have already discussed the importance of choosing the right mechanisms for your use-case. But the abundance of TSN mechanisms, while making them more interesting and versatile for different industries, has also increased the complexity on how to handle their configuration and management.

To address those issues, the amendment IEEE Std 802.1Qcc-2018, introduced some guidelines for the configuration in Clause 46, where three different configuration models where defined: the fully distributed model, the centralized network/distributed user model and the fully centralized network.

In the fully distributed model end-stations communicate directly to the network their user requirements and such requirements are propagated peer to peer using a TSN user/network protocol. Each node will then manage its own resources using the information that is locally available. This is the original AVB approach and for that the Stream Reservation Protocol was used to configure the Credit-Based Shaper.

However there are TSN mechanisms that require a network-wide knowledge for a proper configuration, such is the case for Scheduled Traffic. Additionally, this centralized view of the network can be necessary to optimize the performance in demanding use-cases. To satisfy these needs, the two other configuration models, include a CNC (Centralized Network Configuration) entity that has complete view of the topology and capabilities of all the nodes and thus is able to generate global configuration for the network.

In the centralized network/distributed user model, the end-stations still communicate directly to the network their user requirements, but then the edge nodes forward directly the information to the CNC, that as described before, is able to compute adequate configuration. In the fully centralized model, the end-stations communicate their user requirements to another entity, the CUC (Centralized User Configuration), that in time forward the information directly to the CNC.

For both centralized models, the CNC configures the bridges using a network management protocol. SNMP has been traditionally the choice for network management protocol, specially in the field of Industrial Automation, and because of that MIB models were developed for all mechanisms. However, NETCONF is emerging as the new default management protocol, presenting advantages over SNMP, such as datastore view of the configuration and consistency checks for robust configuration changes. To support the growing popularity of NETCONF, there is an on-going effort in the TSN TG to standardize YANG models for the main TSN mechanisms – starting with IEEE Std 802.1Qcp, that defined the based bridge model, and subsequent projects adding YANG models for Scheduled Traffic, Frame Preemption, Per-Stream Filtering and Policing (P802.1Qcw), Stream Identification, Frame Replication and Elimination for Reliability (IEEE Std 802.1CBcv-2021) or LLDP (IEEE Std 802.1ABcu-2021).

Despite these efforts, the NETCONF/YANG ecosystem is still not fully realized, with some notorious mechanisms still lacking a standard YANG model (Credit-Based Shaper) and different approaches for other aspects of the network such as the topology and routing. Additionally, the application to these concepts in different use-cases is bringing up new requirements for the configuration in TSN, such is the case with the upcoming Aerospace profile, where the need for a single-file configuration file was introduced (you can find HERE our contribution in this topic).

In TSN.studio, we understand the complexity of TSN configuration and want to help you find a seamless configuration approach that works for you.