CompTIA Security+ All-in-One Exam Guide (Exam SY0-301), 3rd Edition, 3rd Edition

OSI Model

To facilitate cross-vendor and multicompany communication, in 1984 the International Organization for Standardization (ISO) created the Open Systems Interconnection (OSI) model for networking. The OSI model is probably the most referenced and widely discussed model in networking. Although it never fully caught on in North America, portions of it have been adopted as reference points, even to the extent of being incorporated into company names. Layer 2, layer 3, network layer, level 3—these are all references to portions of the OSI model. These references allow people to communicate in a clear and unambiguous fashion when speaking of abstract and out of context issues. These references provide context to detail in the complex arena of ...