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A cable with an attached to a, used for Ethernet Ethernet is a family of technologies commonly used in (LAN), (MAN) and (WAN). It was commercially introduced in 1980 and first standardized in 1983 as, and has since been refined to support higher and longer link distances. Over time, Ethernet has largely replaced competing wired LAN technologies such as, and. The original Ethernet uses as a, while the newer Ethernet variants use and links in conjunction with. Over the course of its history, Ethernet data transfer rates have been increased from the original 2.94 (Mbit/s) to the latest 400 (Gbit/s).

The comprise several wiring and signaling variants of the in use with Ethernet. Systems communicating over Ethernet divide a stream of data into shorter pieces called.

Each frame contains source and destination addresses, and so that damaged frames can be detected and discarded; most often, higher-layer protocols trigger of lost frames. As per the, Ethernet provides services up to and including the.

Since its commercial release, Ethernet has retained a good degree of. Features such as the 48-bit and format have influenced other networking protocols. The primary alternative for some uses of contemporary LANs is, a wireless protocol standardized as. Etherpocket-SP Ethernet adapter (circa 1990). Supports both coaxial () and twisted pair () cables.

Power is drawn from a passthrough cable. Ethernet was developed at between 1973 and 1974.

It was inspired by, which had studied as part of his PhD dissertation. The idea was first documented in a memo that Metcalfe wrote on May 22, 1973, where he named it after the disproven as an 'omnipresent, completely-passive medium for the propagation of electromagnetic waves'. In 1975, filed a patent application listing Metcalfe,,, and as inventors. In 1976, after the system was deployed at PARC, Metcalfe and Boggs published a seminal paper. Metcalfe left Xerox in June 1979 to form. He convinced (DEC),, and Xerox to work together to promote Ethernet as a standard. The so-called 'DIX' standard, for 'Digital/Intel/Xerox', specified 10 Mbit/s Ethernet, with 48-bit destination and source addresses and a global 16-bit -type field.

It was published on September 30, 1980 as 'The Ethernet, A Local Area Network. Data Link Layer and Physical Layer Specifications'.

Version 2 was published in November, 1982 and defines what has become known as. Formal proceeded at the same time and resulted in the publication of IEEE 802.3 on June 23, 1983. Ethernet initially competed with two largely proprietary systems, and. Because Ethernet was able to adapt to market realities and shift to inexpensive and ubiquitous wiring, these soon found themselves competing in a market inundated by Ethernet products, and, by the end of the 1980s, Ethernet was clearly the dominant network technology. In the process, 3Com became a major company.

3Com shipped its first 10 Mbit/s Ethernet 3C100 in March 1981, and that year started selling adapters for and, as well as -based Intel and computers.: 9 This was followed quickly by DEC's to Ethernet adapter, which DEC sold and used internally to build its own corporate network, which reached over 10,000 nodes by 1986, making it one of the largest computer networks in the world at that time. An Ethernet adapter card for the IBM PC was released in 1982, and, by 1985, 3Com had sold 100,000. Based Ethernet adapters were produced for a time, with drivers for DOS and Windows.

Free Download Program Best The Back Horn Rar there. By the early 1990s, Ethernet became so prevalent that it was a must-have feature for modern computers, and Ethernet ports began to appear on some PCs and most. This process was greatly sped up with the introduction of 10BASE-T and its relatively small, at which point Ethernet ports appeared even on low-end motherboards. Since then, Ethernet technology has evolved to meet new bandwidth and market requirements. In addition to computers, Ethernet is now used to interconnect appliances and other.

As it is used in industrial applications and is quickly replacing legacy data transmission systems in the world's telecommunications networks. By 2010, the market for Ethernet equipment amounted to over $16 billion per year. Standardization [ ].

• • • Ethernet evolved to include higher bandwidth, improved methods, and different physical media. The coaxial cable was replaced with point-to-point links connected. Ethernet stations communicate by sending each other data packets: blocks of data individually sent and delivered. As with other LANs, each Ethernet station is given a 48-bit.

The MAC addresses are used to specify both the destination and the source of each data packet. Ethernet establishes link level connections, which can be defined using both the destination and source addresses. On reception of a transmission, the receiver uses the destination address to determine whether the transmission is relevant to the station or should be ignored. A network interface normally does not accept packets addressed to other Ethernet stations. Adapters come programmed with a globally unique address. An field in each frame is used by the operating system on the receiving station to select the appropriate protocol module (e.g., an version such as ). Ethernet frames are said to be self-identifying, because of the frame type.

Self-identifying frames make it possible to intermix multiple protocols on the same physical network and allow a single computer to use multiple protocols together. Despite the evolution of Ethernet technology, all generations of Ethernet (excluding early experimental versions) use the same frame formats. Mixed-speed networks can be built using Ethernet switches and repeaters supporting the desired Ethernet variants.

Due to the ubiquity of Ethernet, the ever-decreasing cost of the hardware needed to support it, and the reduced panel space needed by twisted pair Ethernet, most manufacturers now build Ethernet interfaces directly into, eliminating the need for installation of a separate network card. Shared media [ ]. Older Ethernet equipment. Clockwise from top-left: An Ethernet transceiver with an in-line adapter, a similar model transceiver with a adapter, an cable, a different style of transceiver with 10BASE2 T-connector, two 10BASE5 end fittings (), an orange 'vampire tap' installation tool (which includes a specialized drill bit at one end and a socket wrench at the other), and an early model 10BASE5 transceiver (h4000) manufactured by DEC. The short length of yellow 10BASE5 cable has one end fitted with a N connector and the other end prepared to have a N connector shell installed; the half-black, half-grey rectangular object through which the cable passes is an installed vampire tap. Ethernet was originally based on the idea of computers communicating over a shared coaxial cable acting as a broadcast transmission medium. The method used was similar to those used in radio systems, with the common cable providing the communication channel likened to the in 19th century physics, and it was from this reference that the name 'Ethernet' was derived.

Original Ethernet's shared (the shared medium) traversed a building or campus to every attached machine. A scheme known as (CSMA/CD) governed the way the computers shared the channel. This scheme was simpler than competing or technologies. Computers are connected to an (AUI), which is in turn connected to the cable (with the transceiver is integrated into the network adapter). While a simple passive wire is highly reliable for small networks, it is not reliable for large extended networks, where damage to the wire in a single place, or a single bad connector, can make the whole Ethernet segment unusable.

Through the first half of the 1980s, Ethernet's implementation used a coaxial cable 0.375 inches (9.5 mm) in diameter, later called 'thick Ethernet' or 'thicknet'. Its successor,, called 'thin Ethernet' or 'thinnet', used the coaxial cable. The emphasis was on making installation of the cable easier and less costly.: 57 Since all communication happens on the same wire, any information sent by one computer is received by all, even if that information is intended for just one destination. The network interface card interrupts the only when applicable packets are received: the card ignores information not addressed to it. Use of a single cable also means that the data bandwidth is shared, such that, for example, available data bandwidth to each device is halved when two stations are simultaneously active. A collision happens when two stations attempt to transmit at the same time. They corrupt transmitted data and require stations to re-transmit.

The lost data and re-transmission reduces throughput. In the worst case, where multiple active hosts connected with maximum allowed cable length attempt to transmit many short frames, excessive collisions can reduce throughput dramatically. However, a report in 1980 studied performance of an existing Ethernet installation under both normal and artificially generated heavy load. The report claimed that 98% throughput on the LAN was observed. This is in contrast with LANs (token ring, token bus), all of which suffer throughput degradation as each new node comes into the LAN, due to token waits. This report was controversial, as modeling showed that collision-based networks theoretically became unstable under loads as low as 37% of nominal capacity. Many early researchers failed to understand these results.

Performance on real networks is significantly better. In a modern Ethernet, the stations do not all share one channel through a shared cable or a simple repeater hub; instead, each station communicates with a switch, which in turn forwards that traffic to the destination station. In this topology, collisions are only possible if station and switch attempt to communicate with each other at the same time, and collisions are limited to this link. Furthermore, the standard introduced a mode of operation which became common with and the de facto standard with. In full duplex, switch and station can send and receive simultaneously, and therefore modern Ethernets are completely collision-free.

Comparison between original Ethernet and modern Ethernet. Main article: For signal degradation and timing reasons, coaxial have a restricted size. Somewhat larger networks can be built by using an.

Early repeaters had only two ports, allowing, at most, a doubling of network size. Once repeaters with more than two ports became available, it was possible to wire the network in a. Early experiments with star topologies (called 'Fibernet') using were published by 1978. Shared cable Ethernet is always hard to install in offices because its bus topology is in conflict with the star topology cable plans designed into buildings for telephony. Modifying Ethernet to conform to telephone wiring already installed in commercial buildings provided another opportunity to lower costs, expand the installed base, and leverage building design, and, thus, twisted-pair Ethernet was the next logical development in the mid-1980s. Ethernet on unshielded twisted-pair cables (UTP) began with at 1 Mbit/s in the mid-1980s. In 1987 introduced the first twisted-pair Ethernet at 10 Mbit/s in a star-wired cabling topology with a central hub, later called.

These evolved into 10BASE-T, which was designed for point-to-point links only, and all termination was built into the device. This changed repeaters from a specialist device used at the center of large networks to a device that every twisted pair-based network with more than two machines had to use. The tree structure that resulted from this made Ethernet networks easier to maintain by preventing most faults with one peer or its associated cable from affecting other devices on the network.

Despite the physical star topology and the presence of separate transmit and receive channels in the twisted pair and fiber media, repeater-based Ethernet networks still use half-duplex and CSMA/CD, with only minimal activity by the repeater, primarily generation of the in dealing with packet collisions. Every packet is sent to every other port on the repeater, so bandwidth and security problems are not addressed. The total throughput of the repeater is limited to that of a single link, and all links must operate at the same speed. Bridging and switching [ ]. Main articles: and While repeaters can isolate some aspects of, such as cable breakages, they still forward all traffic to all Ethernet devices. This creates practical limits on how many machines can communicate on an Ethernet network.

The entire network is one, and all hosts have to be able to detect collisions anywhere on the network. This limits the number of repeaters between the farthest nodes. Segments joined by repeaters have to all operate at the same speed, making phased-in upgrades impossible.

To alleviate these problems, bridging was created to communicate at the data link layer while isolating the physical layer. With bridging, only well-formed Ethernet packets are forwarded from one Ethernet segment to another; collisions and packet errors are isolated. At initial startup, Ethernet bridges (and switches) work somewhat like Ethernet repeaters, passing all traffic between segments. By observing the source addresses of incoming frames, the bridge then builds an address table associating addresses to segments. Once an address is learned, the bridge forwards network traffic destined for that address only to the associated segment, improving overall performance. Traffic is still forwarded to all network segments. Bridges also overcome the limits on total segments between two hosts and allow the mixing of speeds, both of which are critical to deployment of.

In 1989, the networking company (acquired by in 1994) introduced their EtherSwitch, the first Ethernet switch. This works somewhat differently from an Ethernet bridge, where only the header of the incoming packet is examined before it is either dropped or forwarded to another segment. This greatly reduces the forwarding latency and the processing load on the network device. One drawback of this method is that packets that have been corrupted are still propagated through the network, so a station can continue to disrupt the entire network. The eventual remedy for this was a return to the original approach of bridging, where the packet would be read into a buffer on the switch in its entirety, verified against its checksum and then forwarded, but using more powerful.

Hence, the bridging is then done in hardware, allowing packets to be forwarded at full wire speed. When a twisted pair or fiber link segment is used and neither end is connected to a repeater, Ethernet becomes possible over that segment. In full-duplex mode, both devices can transmit and receive to and from each other at the same time, and there is no collision domain. This doubles the aggregate bandwidth of the link and is sometimes advertised as double the link speed (for example, 200 Mbit/s). The elimination of the collision domain for these connections also means that all the link's bandwidth can be used by the two devices on that segment and that segment length is not limited by the need for correct collision detection. Since packets are typically delivered only to the port they are intended for, traffic on a switched Ethernet is less public than on shared-medium Ethernet.

Despite this, switched Ethernet should still be regarded as an insecure network technology, because it is easy to subvert switched Ethernet systems by means such as and. The bandwidth advantages, the improved isolation of devices from each other, the ability to easily mix different speeds of devices and the elimination of the chaining limits inherent in non-switched Ethernet have made switched Ethernet the dominant network technology. Advanced networking [ ]. A core Ethernet switch Simple switched Ethernet networks, while a great improvement over repeater-based Ethernet, suffer from single points of failure, attacks that trick switches or hosts into sending data to a machine even if it is not intended for it, scalability and security issues with regard to, and traffic, and bandwidth choke points where a lot of traffic is forced down a single link. [ ] Advanced networking features in switches use (SPB) or the (STP) to maintain a loop-free, meshed network, allowing physical loops for redundancy (STP) or load-balancing (SPB). Advanced networking features also ensure port security, provide protection features such as lockdown and broadcast radiation filtering, use to keep different classes of users separate while using the same physical infrastructure, employ to route between different classes, and use to add bandwidth to overloaded links and to provide some redundancy. () includes the use of the to allow larger networks with shortest path routes between devices.

In 2012, it was stated by David Allan and Nigel Bragg, in 802.1aq Shortest Path Bridging Design and Evolution: The Architect's Perspective that shortest path bridging is one of the most significant enhancements in Ethernet's history. Ethernet has replaced as the most popular system interconnect of supercomputers. Error conditions [ ] Jabber [ ] A node that is sending longer than the maximum transmission window for an Ethernet packet is considered to be jabbering. Depending on the physical topology, jabber detection and remedy differ somewhat.

• An is required to detect and stop abnormally long transmission from the (longer than 20–150 ms) in order to prevent permanent network disruption. • On an electrically shared medium (10BASE5, 10BASE2, 1BASE5), jabber can only be detected by each end node, stopping reception. No further remedy is possible. • A repeater/repeater hub uses a jabber timer that ends retransmission to the other ports when it expires. The timer runs for 25,000 to 50,000 bit times for 1 Mbit/s, 40,000 to 75,000 bit times for 10 and 100 Mbit/s, and 80,000 to 150,000 bit times for 1 Gbit/s. Jabbering ports are partitioned off the network until a carrier is no longer detected. • End nodes utilizing a MAC layer will usually detect an oversized Ethernet frame and cease receiving.

A bridge/switch will not forward the frame. • A non-uniform frame size configuration in the network using may be detected as jabber by end nodes.

• A packet detected as jabber by an upstream repeater and subsequently cut off has an invalid and is dropped. Runt frames [ ] • are packets or frames smaller than the minimum allowed size.

They are dropped and not propagated. Varieties of Ethernet [ ]. Main article: The Ethernet physical layer evolved over a considerable time span and encompasses coaxial, twisted pair and fiber-optic physical media interfaces, with speeds from 10 Mbit/s to 100 Gbit/s, with expected by 2018.

The first introduction of twisted-pair CSMA/CD was, standardized as 802.3 1BASE5; while 1BASE5 had little market penetration, it defined the physical apparatus (wire, plug/jack, pin-out, and wiring plan) that would be carried over to 10BASE-T. The most common forms used are. All three use twisted pair cables and. They run at 10 Mbit/s, 100 Mbit/s, and 1 Gbit/s, respectively. Variants of Ethernet are also very common in larger networks, offering high performance, better electrical isolation and longer distance (tens of kilometers with some versions).

In general, network software will work similarly on all varieties. Frame structure [ ]. Main article: In IEEE 802.3, a is called a packet or frame. Packet is used to describe the overall transmission unit and includes the, (SFD) and carrier extension (if present). The frame begins after the start frame delimiter with a frame header featuring source and destination MAC addresses and giving either the protocol type for the payload protocol or the length of the payload. The middle section of the frame consists of payload data including any headers for other protocols (for example, ) carried in the frame.

The frame ends with a 32-bit, which is used to detect corruption of.: sections 3.1.1 and 3.2 Notably, Ethernet packets have no, leading to possible problems in the presence of a. Autonegotiation [ ]. • The experimental Ethernet described in the 1976 paper ran at 2.94 Mbit/s and has eight-bit destination and source address fields, so the original Ethernet addresses are not the they are today. By software convention, the 16 bits after the destination and source address fields specify a 'packet type', but, as the paper says, 'different protocols use disjoint sets of packet types'. Thus the original packet types could vary within each different protocol.

This is in contrast to the in the IEEE Ethernet standard, which specifies the protocol being used. • Unless it is put into.

• In some cases, the factory-assigned address can be overridden, either to avoid an address change when an adapter is replaced or to use locally administered addresses. • There are fundamental differences between wireless and wired shared-medium communication, such as the fact that it is much easier to detect collisions in a wired system than a wireless system.

• In a CSMA/CD system packets must be large enough to guarantee that the leading edge of the propagating wave of a message gets to all parts of the medium and back again before the transmitter stops transmitting, guaranteeing that (two or more packets initiated within a window of time that forced them to overlap) are discovered. As a result, the minimum packet size and the physical medium's total length are closely linked. • Multipoint systems are also prone to strange failure modes when an electrical discontinuity reflects the signal in such a manner that some nodes would work properly, while others work slowly because of excessive retries or not at all. See for an explanation.

These could be much more difficult to diagnose than a complete failure of the segment. • This 'one speaks, all listen' property is a security weakness of shared-medium Ethernet, since a node on an Ethernet network can eavesdrop on all traffic on the wire if it so chooses. • Unless it is put into. • The term switch was invented by device manufacturers and does not appear in the 802.3 standard.

• This is misleading, as performance will double only if traffic patterns are symmetrical. • The carrier extension is defined to assist collision detection on shared-media gigabit Ethernet. References [ ]. • Ralph Santitoro (2003). Retrieved 2016-01-09.

• ^ (Press release). June 24, 2013. Retrieved January 11, 2014. • Xerox (August 1976).

Retrieved 25 August 2015. Kozierok (2005-09-20).. Retrieved 2016-01-09. • Joe Jensen (2007-10-26).. Retrieved 2016-01-09. Retrieved September 10, 2011.

Smithsonian National Museum of American History. Retrieved September 2, 2007. Brock (September 25, 2003). The Second Information Revolution. Harvard University Press.

• Cade Metz (March 13, 2009).. The Register: 2. Retrieved March 4, 2013. • Mary Bellis.. Retrieved September 10, 2011. • 'Multipoint data communication system (with collision detection)' •; (July 1976).

19 (7): 395–405.. Dalal; David D. Redell; (August 1982). IEEE Computer. 15 (8): 14–26.. • ^ von Burg, Urs; Kenney, Martin (December 2003). Industry & Innovation.

10 (4): 351–375.. (PDF) from the original on March 22, 2012. Retrieved 17 February 2014. • ^ Digital Equipment Corporation; Intel Corporation; Xerox Corporation (30 September 1980).

Xerox Corporation. Skyrim Free Pc Full Version 2012 Olympic Gymnastics. Retrieved 2011-12-10. • Digital Equipment Corporation; Intel Corporation; Xerox Corporation (November 1982). Xerox Corporation. Retrieved 2011-12-10. • ^ Robert Breyer; Sean Riley (1999). Switched, Fast, and Gigabit Ethernet.

• Jamie Parker Pearson (1992). Digital at Work. Digital Press. • Rick Merritt (December 20, 2010)..

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IEEE 802 was formed in February 1980. • IEEE 802.3-2008, p.iv •.. Retrieved 2015-07-08. • Jim Duffy (2009-04-20)... Retrieved 2016-01-01. Internetworking with TCP/IP – Principles, Protocols and Architecture (4th ed.).

Prentice Hall.. 2.4.9 – Ethernet Hardware Addresses, p. 29, explains the filtering. • Iljitsch van Beijnum... Retrieved July 15, 2011.

All aspects of Ethernet were changed: its MAC procedure, the bit encoding, the wiring. Only the packet format has remained the same. •, Lantronix, retrieved 2016-01-01 • Geetaj Channana (November 1, 2004).. Retrieved October 22, 2010.

While comparing motherboards in the last issue we found that all motherboards support Ethernet connection on board. Spurgeon (2000). Ethernet: The Definitive Guide. • Heinz-Gerd Hegering; Alfred Lapple (1993). Ethernet: Building a Communications Infrastructure. •, Lantronix, retrieved 2016-01-01 • Shoch, John F.; Hupp, Jon A. (December 1980)..

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Stanford University Press. Retrieved October 22, 2010. Respondents were first asked about their current and planned desktop LAN attachment standards. The results were clear—switched Fast Ethernet is the dominant choice for desktop connectivity to the network • Allan, David; Bragg, Nigel (2012).. New York: Wiley.. Retrieved 2016-08-08. InfiniBand technology is now found on 205 systems, down from 235 systems, and is now the second most-used internal system interconnect technology.

Gigabit Ethernet has risen to 218 systems up from 182 systems, in large part thanks to 176 systems now using 10G interfaces. • IEEE 802.3 8.2 MAU functional specifications • IEEE 802.3 8.2.1.5 Jabber function requirements • IEEE 802.3 12.4.3.2.3 Jabber function • IEEE 802.3 9.6.5 MAU Jabber Lockup Protection • IEEE 802.3 27.3.2.1.4 Timers • IEEE 802.3 41.2.2.1.4 Timers • IEEE 802.3 27.3.1.7 Receive jabber functional requirements • IEEE 802.1 Table C-1—Largest frame base values • (PDF). IEEE 802.3bs Task Force. Retrieved 2017-01-08. Retrieved 2014-11-11. IEEE Standards Association.

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Ethernet: The Definitive Guide. O'Reilly Media.. External links [ ] Wikimedia Commons has media related to.