The term networking model, or networking architecture, refers to an organized set of documents. Individually, these documents describe one small function required for a network. These documents may define a protocol, which is a set of logical rules that devices must follow to communicate. Other documents may define some physical requirements for networking, for example, it may define the voltage and current levels used on a particular cable. Collectively, the documents referenced in a networking model define all the details of how to create a complete working network.
The CCNA exams include detailed coverage of one networking model—the Transmission Control Protocol/Internet Protocol, or TCP/IP. TCP/IP is the most pervasively used networking model in the history of networking. You can find support for TCP/IP on practically every computer operating system in existence today, from mobile phones to mainframe computers. Almost every network built using Cisco products today supports TCP/IP. Not surprisingly, the CCNA exams focus heavily on TCP/IP.The ICND1 exam, and the ICND2 exam to a small extent, also covers a second networking model, called the Open System Interconnection (OSI) reference model. Historically, OSI was the first large effort to create a vendor-neutral networking model, a model that was intended to be used by any and every computer in the world. Because OSI was the first major effort to create a vendor-neutral networking architectural model, many of the terms used in networking today come from the OSI model.
The CCNA exams include detailed coverage of one networking model—the Transmission Control Protocol/Internet Protocol, or TCP/IP. TCP/IP is the most pervasively used networking model in the history of networking. You can find support for TCP/IP on practically every computer operating system in existence today, from mobile phones to mainframe computers. Almost every network built using Cisco products today supports TCP/IP. Not surprisingly, the CCNA exams focus heavily on TCP/IP.The ICND1 exam, and the ICND2 exam to a small extent, also covers a second networking model, called the Open System Interconnection (OSI) reference model. Historically, OSI was the first large effort to create a vendor-neutral networking model, a model that was intended to be used by any and every computer in the world. Because OSI was the first major effort to create a vendor-neutral networking architectural model, many of the terms used in networking today come from the OSI model.