The OSI model is a seven-layer framework that standardizes how data travels between applications across any network. Created by the International Organization for Standardization, it breaks the complex task of network communication into manageable layers, each with a clearly defined responsibility. In telecom, every protocol you encounter maps to one or more of these layers. Whether you are troubleshooting a dropped call, analyzing signaling flows, or designing a new network function, the OSI model gives you a shared vocabulary and a systematic way to isolate problems at the correct layer.