This document describes the Passive Ethernet Network (PEN) solution, including its introduction, typical deployment scenarios, deployment guide, typical faults, and FAQs. Leveraging mainstream Ethernet protocols, the Xingmai PEN solution uses optical fibers to implement passive data transmission without the need of any ELV room. This solution. Figure 3-1 Structured cabling system ● A PEN mainly contains PEN central switches, PEN passive aggregation modules, and access switches. You can select a networking scheme according to the customer's service characteristics and network reliability requirements.