Copper vs. Fiber: Physical Layer & Security | OT Security Module 1.5

Before we get into IP addresses, protocols, and firewalls, we need to talk about the physical layer — the actual cables that networks run on. In industrial environments, the choice of cable matters more than most people realize, both for performance and for security. We cover Cat5e and Cat6 copper Ethernet — their speed limits and 100-meter distance constraint — and why copper is vulnerable to electrical interference from VFDs, motors, and arc flash in industrial environments. We also cover fiber optic cable, including multi-mode versus single-mode and their respective distance capabilities, and an often-overlooked physical layer security risk: unprotected switch ports and unlabeled cables. By the end of this video, you'll know when fiber is the better choice over copper, and why undocumented cabling is one of the most common security problems in aging OT facilities. 🕐 Chapters: 0:00 – Introduction: the physical layer matters in industrial environments 0:20 – Two main types of network media: copper and fiber 0:29 – Cat5e and Cat6 copper Ethernet explained 0:35 – RJ45 connectors, speeds & field termination 0:53 – The 100-meter distance limit of copper 1:17 – Electrical interference: copper as an antenna in industrial environments 1:25 – VFDs, motors, high voltage & arc flash — the EMI problem 1:39 – Why fiber is the better choice in noisy environments 1:43 – Fiber transmits light, not electricity — why that changes everything 1:54 – Multi-mode fiber: up to 550 meters, ideal for in-building runs 2:08 – Single-mode fiber: kilometers of range for remote sites & substations 2:20 – Fiber is completely immune to electromagnetic interference 2:32 – No ground loops, no arc flash corruption 2:39 – Where fiber belongs: substations, MCCs & heavy electrical areas 2:48 – Physical layer security: the overlooked risk 3:05 – Unprotected switch ports — plug in and you're on the network 3:14 – Unlabeled cables & undocumented infrastructure in aging OT facilities 3:40 – Fiber's covert tap advantage over copper 4:04 – What's next: serial communications — RS232, RS485, RS422 & legacy devices Part of Module 1: Networking Fundamentals Full course playlist: [link] If this was useful, subscribe for more content like this. #OTSecurity #IndustrialCybersecurity #ICS #SCADA #OTNetworking