Studium vlastností 50Gb-PON při různých scénářích zatížení sítě

Abstract

This bachelor thesis investigates the properties of the 50G-PON passive optical network under different network load scenarios in laboratory conditions. The theoretical part describes the 50G-PON technology in the context of previous generations of ITU-T standards, its coexistence mechanisms, layer model, and key innovations in the common transmission convergence layer. The practical part covers the design and construction of a real optical distribution network of 12.5 km length with a Huawei MA5800-X7 central unit and OptiXstar M990 end units, on which measurements of chromatic and polarization mode dispersion as well as direct and indirect attenuation measurements were performed. A Telegraf — InfluxDB — Grafana analytical system with SNMPv3 monitoring was deployed for telemetry data capture and analysis. Load testing was conducted using three methodologies covering different layers of the OSI model: ITU-T Y.1564 at the link layer, IETF RFC 6349 and the iPerf3 software tool at the transport layer. The results demonstrated error-free operation across all tested layers of the OSI model, full achievement of the committed information rate (CIR) of all tested services, and identified the 25~Gbit/s ONT interface as the bottleneck. Simultaneous operation of two end units confirmed capacity sharing via the dynamic bandwidth assignment mechanism and revealed differences in TCP congestion control behaviour between the Linux and Windows operating systems.