Performance Evaluation of Single-Board Embedded Linux Platforms as Asterisk Servers for Phone of Things (PoT) Applications

Phone of things (PoT) is a novel idea for loT systems connectivity that allows legacy and non-loT-enabled devices to be interfaced through the mature and ubiquitous telephone network infrastructure. This paper evaluates the performance of the Raspberry Pi board families, embedded Linux platforms based on ARM processors, on processing VolP calls for PoT applications. The paper assesses and contrasts the ability of the boards in handling passthrough and trans coded VolP calls. Based on the obtained results, the paper proposes best practices for employing the boards as Asterisk servers and advocates the maximum number of simultaneous calls at different scenarios to preserve the hardware safety and maintain better performance regarding system stability and VolP call quality measurements. The results show that Raspberry Pi 4 B can gracefully han-dle up to 364 active passthrough channels (equivalent to 182 simultaneous calls). Nevertheless, Pi Zero W, the least powerful version of the Raspberry Pi, can gracefully handle up to 24 active passthrough channels. The results promote the utilization of embedded Linux platforms as appropriate, tiny form factor, and cost-effective candidates to act as PoT gateways in homes and small-to-medium sized business domains.