Layer 8 is a term used to refer to "user" or "political" layer on top of the 7-layer OSI model of computer networking. The OSI model is a 7-layer abstract model that describes an architecture of data communications for networked computers. The layers build upon each other, allowing for abstraction of specific functions in each one. The top layer is the Application Layer describing methods and protocols of software applications. It is then held that the user is the 8th layer. Network appliances vendor like Cyberoam claim that Layer 8 allows IT administrators to identify users, control Internet activity of users in the network, set user based policies and generate reports by username. According to Bruce Schneier and RSA:
Since the OSI layer numbers are commonly used to discuss networking topics, a troubleshooter may describe an issue caused by a user to be a layer 8 issue, similar to the PEBKAC acronym, the ID-Ten-T Error and also PICNIC. Political economic theory holds that the 8th layer is important to understanding the OSI Model. Political policies such as network neutrality, spectrum management, and digital inclusion all shape the technologies comprising layers 1–7 of the OSI Model. An 8th layer has also been referenced to physical controllers containing an external hardware device which interacts with an OSI model network. An example of this is ALI in Profibus. A network guru T-shirt from the 1980s shows Layer 8 as the "financial" layer, and Layer 9 as the "political" layer. The design was credited to Evi Nemeth.
Similar pseudo-layers for TCP/IP
In the TCP/IP model, the four-layer model of the Internet, a fifth layer is sometimes analogously described as the political layer, and the sixth as the religious layer. This appears in a humorous April Fools' Day RFC, RFC 2321, published in 1998.
Other uses
Linux Gazette carries a regular column called Layer 8 Linux Security.
Layers 8, 9, and 10 are sometimes used to represent individuals, organizations, and governments for the user layer of Service Oriented Architectures. See OSI User Layers figure for details.
User-in-the-loop is a serious concept including Layer 8 as a system level model.
In 2016, a company shipped a product called Layer8 to "bridge the universal divide between PC users and IT managers".
