It takes a lot of functions and systems to get a network going and keep it running efficiently. When it is done correctly, end users are virtually unaware of the network itself and just expect easy (and secure) access to their resources. Providing all the services required to keep the network running in this manner means that many infrastructure devices are required.
Devices within the OSI Model
Infrastructure devices are said to function at specific layers of the OSI Model based on the nature of the information they are designed to process.
Layer 1 devices
As described earlier in this chapter, Layer 1 of the OSI Model is the Physical layer. At the Physical layer, no intelligence is required, only physical connections between systems, ...