Open Systems Interconnection (Osi) Model and How It Relates to a Network.

The International Organization for Standardization developed the Open Systems Interconnection model otherwise known as the OSI model. Layering is the structuring technique used by the OSI model. The layering is partitioned into a hierarchical set, which contains the communication functions. Mitchell (2010) states, “The OSI is an abstract model of how network protocols and equipment should communicate and work together.” The OSI model consists of seven layers where each higher layer depends on the lower layer to perform more primitive functions while concealing the details of those functions. The seven layers from the bottom up are as follows: physical, data link, network, transport, session, presentation, and application. Each layer has a responsibility and depends on the lower layer to get the message to the intended recipient.

The seven layers are grouped into two groups known as the upper and lower layers. The upper layers consist of the application, presentation, and session layers. The lower layers consist of the transport, network, data link, and physical layers. According to Mitchell (2010) the upper layers performs application-specific functions such as data formatting, encryption, and connection management. Some technology examples that exist in the upper layers of the OSI are HTTP, SSL, and NFS. In addition, Mitchell states that the lower layers is where the more primitive functions related to the network, such as routing, addressing, and flow control. Some technology examples that exist in the upper layers of the OSI are TCP, IP, and Ethernet. The OSI model simplifies network protocols design because it breaks down the network communications into smaller pieces.

The OSI model’s first two layers (physical and data link) are where most of the physical network details are handled. This is also where most of the WAN protocols function at to connect the devices that will create a network and allow it to communicate with all the devices. Examples of...