PTN, OTN, WDM explained

🧩 Overview Layer Technology Type Core Function Packet Layer (L2–L2.5) PTN Packet-based Efficiently transport and manage packet (Ethernet/IP/MPLS) traffic Digital Optical Layer (L1.5) OTN Digital frame-based Encapsulate client signals (Ethernet, SDH, Fibre Channel, etc.) into standardized optical containers Physical Optical…