Ethernet Standards PDF

2.1.2 Ethernet Standards Over the years, many protocols, standards, and products have been developed to implement the functions of the Physical and Data Link layers of the OSI model. A standard must define cable and connector specifications and define schemes for modulation and encoding. The I...

2.1.2 Ethernet Standards Over the years, many protocols, standards, and products have been developed to implement the functions of the Physical and Data Link layers of the OSI model. A standard must define cable and connector specifications and define schemes for modulation and encoding. The Institute of Electrical and Electronics Engineers (IEEE) 802.3 Ethernet standards (ieee802.org/3) are very widely used on both LANs and WANs. Ethernet standards provide assurance that network cabling will meet the bandwidth requirements of applications. These Ethernet media specifications are named using a three-part convention, which is often referred to as xBASE-y. This describes the following: The speed or bit rate in megabits per second (Mbps) or gigabits per second (Gbps). The signal mode (baseband or broadband). All mainstream types of Ethernet use baseband transmissions, so you will only see specifications of the form xBASE-y. A designator for the media type. For example, 10BASE-T denotes an early implementation that works at 10 Mbps (10), uses a baseband signal (BASE), and runs over twisted pair copper cabling (-T). Copper cable is used to transmit electrical signals. The cable between two nodes creates a low voltage electrical circuit between the interfaces on the nodes. There are two main types of copper cable: twisted pair and coaxial (coax). Copper cable suffers from high attenuation, meaning that the signal quickly loses strength over long links. Twisted pair cable is rated to Category (or "Cat") standards that define what bandwidth it should support, up to a given distance. Copyright © The Computing Technology Industry Association, Inc. All rights reserved.