This chapter addresses many of the networking standards and theories that are used in computer networks, as well as the ports employed by many common applications. This chapter also contains policies and procedural concepts.
This section discusses the Open Systems Interconnection model as a reference point that can be used to describe functionality in a computer network.
Layer 1—The physical layer, also known as Layer 1, deals with the transmission of bits over the network. This includes both copper and fiber cabling, as well as radio frequency when used as part of wireless networks. An unmanaged hub that is simply acting as a repeater is considered a Layer 1 device.
Layer 2—The data link layer, ...