Free Essays on Ethernet

Ethernet In early 1970’s, Xerox Corporation introduced a different networking concept called Ethernet. The thick coaxial media system was the first media system specified in the original Ethernet standard of 1980. Today most sites use twisted-pair media for connections to the desktop. Ethernet is designed to run on a single transmission line to which all stations are connected. As with token ring, Ethernet is peer-to-peer; however no monitoring device is requires. Unlike token ring, Ethernet does not require that stations wait for a token to be passed before transmitting. Stations are able to connect directly to one another and pass data any time there is no activity on the network. The 10-Mbps Ethernet media varieties include the original thick coaxial system, as well as thin coaxial, twisted-pair, and fiber optic systems. The most recent Ethernet standard defines the new 100-Mbps Fast Ethernet systems that operate over twisted-pair and fiber optic media. Picture of the first Ethernet There are several LAN technologies in use today, but Ethernet is by far the most popular. Industry estimates indicate that as of 1994 over 40 million Ethernet nodes had been installed worldwide. The widespread popularity of Ethernet ensures that there is a large market for Ethernet equipment, which also helps keep the technology competitively priced. From the time of the first Ethernet standard, the specifications and the rights to build Ethernet technology have been made easily available to anyone. This openness, combined with the ease of use and robustness of the Ethernet system, resulted in a large Ethernet market and is another reason Ethernet is so widely implemented in the computer industry. The vast majority of computer vendors today equip their products with 10-Mbps Ethernet attachments, making it possible to link all manner of computers with an Ethernet LAN. As the 100-Mbps standard becomes more widely adopted, computers are bei... Free Essays on Ethernet Free Essays on Ethernet Ethernet uses a protocol called CSMA/CD. This stands for Carrier Sense, Multiple Access, Collision Detect. The Multiple Access part means that every station is connected to a single copper wire, or a set of wires that are connected together to form a single data path. The Carrier Sense part says that before transmitting data, a station checks the wire to see if any other station is already sending something. If the LAN appears to be idle, then the station can begin to send data. An Ethernet station sends data at a rate of 10 megabits per second. That bit allows 100 nanoseconds per bit. Light and electricity travel about one foot in a nanosecond. Therefore, after the electric signal for the first bit has traveled about 100 feet down the wire, the station has begun to send the second bit. However, an Ethernet cable can run for hundreds of feet. If two stations are located, say, 250 feet apart on the same cable, and both begin transmitting at the same time, then they will be in the midd le of the third bit before the signal from each reaches the other station. This explains the need for the Collision Detect part. Two stations can begin to send data at the same time, and their signals will collide. When such a collision occurs, the two stations stop transmitting, and try again later after a randomly chosen delay period. While an Ethernet can be built using one common signal wire, such an arrangement is not flexible enough to wire most buildings. Unlike an ordinary telephone circuit, Ethernet wire cannot be just spliced together, connecting one copper wire to another. Ethernet requires a repeater. A repeater is a simple station that is connected to two wires. Any data that it receives on one wire it repeats bit-for-bit on the other wire. When collisions occur, it repeats the collision as well. In common practice, repeaters are used to convert the Ethernet signal from one type of wire to another. In particular, when the connection to the d... Free Essays on Ethernet Ethernet In early 1970’s, Xerox Corporation introduced a different networking concept called Ethernet. The thick coaxial media system was the first media system specified in the original Ethernet standard of 1980. Today most sites use twisted-pair media for connections to the desktop. Ethernet is designed to run on a single transmission line to which all stations are connected. As with token ring, Ethernet is peer-to-peer; however no monitoring device is requires. Unlike token ring, Ethernet does not require that stations wait for a token to be passed before transmitting. Stations are able to connect directly to one another and pass data any time there is no activity on the network. The 10-Mbps Ethernet media varieties include the original thick coaxial system, as well as thin coaxial, twisted-pair, and fiber optic systems. The most recent Ethernet standard defines the new 100-Mbps Fast Ethernet systems that operate over twisted-pair and fiber optic media. Picture of the first Ethernet There are several LAN technologies in use today, but Ethernet is by far the most popular. Industry estimates indicate that as of 1994 over 40 million Ethernet nodes had been installed worldwide. The widespread popularity of Ethernet ensures that there is a large market for Ethernet equipment, which also helps keep the technology competitively priced. From the time of the first Ethernet standard, the specifications and the rights to build Ethernet technology have been made easily available to anyone. This openness, combined with the ease of use and robustness of the Ethernet system, resulted in a large Ethernet market and is another reason Ethernet is so widely implemented in the computer industry. The vast majority of computer vendors today equip their products with 10-Mbps Ethernet attachments, making it possible to link all manner of computers with an Ethernet LAN. As the 100-Mbps standard becomes more widely adopted, computers are bei...