As you know, nowadays Ethernet is the most common network standards.But you may be confused what is Ethernet.
Ethernet is a data link and physical layer protocol defined by the IEEE 802.3 specification. It comes in many flavors, defined by maximum bit rate, mode of transmission and physical transmission medium.
What Is The Background Of Ethernet?
In the early 1980s, Digital Equipment Corporation, Intel, and Xerox developed the Ethernet Local Area Networking format. This technology was soon accepted by the IEEE Committee, creating the 802.3 standard. This standard dictates the use of CSMA/CD (Carrier Sense Multiple Access with Collision Detection) as its accessing scheme. Networks use NIC (network interface card), hub, transceiver, converter, repeater & switch, as well as different types of transmission medias for carrying signals.
A variety of Ethernet types have come and gone over the years, such as the following:
In the mid 1990s, 100BASE-T (unshielded twisted-pair [UTP]) and 100BASE-FX (using fiber) were ubiquitous in the enterprise network, and they still are. Since the start of the millennium, enterprise networks have actively implemented Gigabit Ethernet, 1000BASE-T, in their network. The push for today is 10 Gbps in the core of the enterprise network.
What Is The Basic Ethernet Theory?
Ethernet Theory is a concept of how computers that are not physically connected should communicate with each other for the transmission of data.
1.Ethernet operational theory is quite easy to understand and a simple analogy is helpful to visualize the basics. Imagine a long hallway lined with offices. The hallway represents the physical network, the offices represent the attached stations. When an occupant wishes to speak to another occupant they would lean into the hallway, listen to make sure no one else is engaging in a conversation, then speak out addressing the desired recipient. All other occupants hear the conversation but ignore it knowing it is not directed to them.
2.Returning to our analogy, what if two or more occupants decide to speak at the same time? Naturally the overlapping voices would become garbled and indistinguishable. With Ethernet this is known as a collision. In the CSMA/CD method, CD stands for Collision Detection. If a collision is detected by a transmitting station(s) the rule states: stop transmitting immediately, transmit a jamming signal to inform all other stations to stop, then wait a random period (binary exponential backoff) and re-transmit. Unfortunately, as the quantity of stations increases so does the amount of collisions. This causes the average access time to increase proportionally. This is referred to in the industry as network congestion.
3. Fortunately, there are several ways to alleviate network congestion. One way is that the entire network can be upgraded to Fast Ethernet (100 Mbps) which represents a 10 fold increase in transmission speed. This, however requires upgrading of all components and can be rather expensive. Another approach is to add an Ethernet Switch.
Ethernet is an asynchronous Carrier Sense Multiple Access with Collision Detect (CSMA/CD) protocol/interface, with a payload size of 46-1500 octets. With data rates of tens to hundreds of megabits/second, it is generally not well suited for low-power applications. However, with ubiquitous deployment, internet connectivity, high data rates and limitless range expansibility, Ethernet can accommodate nearly all wired communications requirements. Common applications include:
1. Remote sensing and monitoring;
2. Remote command, control and firmware updating;
3. Bulk data transfer;
4. Live streaming audio, video and media;
5. Public data acquisition (date/time, stock quotes, news releases, etc.