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Future proofing is a very interesting and attractive feature of TSN. It is based on the assump-tion that TSN technology will be developed over many years according to the principles that have already been defined and implemented. Thus, it can be hoped that networks built today will not ‘grow old’ for many years and will not require a major infrastructural overhaul.

Another important feature of TSN is traffic prioritisation. In a TSN network, data of varying degrees of importance from the point of view of security and ensuring production continuity can be transmitted. Some of them must be delivered within a very strict timeframe, while others can reach their destination with a delay without causing any undesirable effects. Mech-anisms to ensure that traffic is handled according to assigned priorities have long been known and used in Ethernet networks. The role is fulfilled by QoS (Quality of Service), which has been successfully used in LAN.

In addition to this, TSN uses mechanisms whereby the transmission of lower-priority data is halted for a certain period of time, during which higher-priority data is transmitted.

Since many events occurring in industrial automation systems are predictable and it is possi-ble to determine with a high degree of precision when they will occur and when the accom-panying data packets will be transmitted, a traffic scheduling mechanism can be used. Sched-uled traffic is handled by means of a task scheduler, according to which the network switches prioritise individual data packets.

Traffic predictability allows TSN devices to implement an inbound traffic control mechanism. It allows devices to reject data they are not expecting, which minimizes the risk of devices being disrupted by data sent from misconfigured devices or by hosts used to attempt an at-tack and destabilise the network.