  We conducted the feasibility analysis of utilizing a highly available
multi-stage architecture for TSN switches used for sending high priority,
mission-critical traffic within a bounded latency instead of traditional
single-stage architectures. To verify the TSN functionality, we implemented the
'strict priority' feature. We evaluated the performance of both architectures
on multiple parameters such as fault tolerance, packet latency, throughput,
reliability, path length effectiveness, and cost per unit. The fault tolerance
analysis demonstrated that the multi-stage architecture fairs better than the
single-stage counterpart. The average latency and throughput performance of
multi-stage architectures, although low, can be considered comparable with
single-stage counterparts. However, the multi-stage architecture fails to meet
the performance of single-stage architectures on parameters such as
reliability, path length effectiveness, and cost-effectiveness. The improved
fault tolerance comes at the cost of increased hardware resources, cost, and
complexity. However, with the advent of cost-effective technologies in hardware
design and efficient architecture designs, the multi-stage switching
architecture-based TSN switches can be made reasonably comparable to
single-stage switching TSN switches. This work gives initial confidence that
the multi-stage architecture can be pursued further for safety-critical systems
that require determinism and reliability in the communication of critical
messages.
