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2.3 | |
Networking Models | |
| 2.3.3 | |
OSI model |
| The early development of networks was
disorganized in many ways. The early 1980s saw tremendous increases in
the number and size of networks. As companies realized the advantages of
using networking technology, networks were added or expanded almost as
rapidly as new network technologies were introduced.
By the mid-1980s, these companies began to experience problems from the rapid expansion. Just as people who do not speak the same language have difficulty communicating with each other, it was difficult for networks that used different specifications and implementations to exchange information. The same problem occurred with the companies that developed private or proprietary networking technologies. Proprietary means that one or a small group of companies controls all usage of the technology. Networking technologies strictly following proprietary rules could not communicate with technologies that followed different proprietary rules. To address the problem of network incompatibility, the International Organization for Standardization (ISO) researched networking models like Digital Equipment Corporation net (DECnet), Systems Network Architecture (SNA), and TCP/IP in order to find a generally applicable set of rules for all networks. Using this research, the ISO created a network model that helps vendors create networks that are compatible with other networks. The Open System Interconnection (OSI) reference model released in 1984
was the descriptive network model that the ISO created. It provided
vendors with a set of standards that ensured greater compatibility and
interoperability among various network technologies produced by
companies around the world.
The OSI reference model has become the primary model for network communications. Although there are other models in existence, most network vendors relate their products to the OSI reference model. This is especially true when they want to educate users on the use of their products. It is considered the best tool available for teaching people about sending and receiving data on a network.
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