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127-489: Ethernet and Wi-Fi are the two most common technologies in use for local area networks. Historical network technologies include ARCNET , Token Ring and AppleTalk . The increasing demand and usage of computers in universities and research labs in the late 1960s generated the need to provide high-speed interconnections between computer systems. A 1970 report from the Lawrence Radiation Laboratory detailing

254-608: A TCP -style reliable connection-oriented transport was needed. Significant differences from TCP were that: The Apple Filing Protocol (AFP), formerly AppleTalk Filing Protocol, is the protocol for communicating with AppleShare file servers. Built on top of AppleTalk Session Protocol (for legacy AFP over DDP) or the Data Stream Interface (for AFP over TCP), it provides services for authenticating users (extensible to different authentication methods including two-way random-number exchange) and for performing operations specific to

381-454: A datagram is called a packet or frame . Packet is used to describe the overall transmission unit and includes the preamble , start frame delimiter (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 the EtherType field giving either the protocol type for the payload protocol or

508-445: A hotspot service. Network topology describes the layout of interconnections between devices and network segments. At the data link layer and physical layer , a wide variety of LAN topologies have been used, including ring , bus , mesh and star . Simple LANs generally consist of cabling and one or more switches . A switch can be connected to a router , cable modem , or ADSL modem for Internet access. A LAN can include

635-436: A wide area network (WAN). Ethernet Ethernet ( / ˈ iː θ ər n ɛ t / EE -thər-net ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3 . Ethernet has since been refined to support higher bit rates ,

762-399: A "Printers" zone that would list all the printers in an organization, or one might want to place that same device in the "2nd Floor" zone to indicate its physical location. Phase II also included changes to the underlying inter-networking protocols to make them less "chatty", which had previously been a serious problem on networks that bridged over wide-area networks. By this point, Apple had

889-559: A "few months". Through this period, Apple was deep in development of the Macintosh computer. During development, engineers had made the decision to use the Zilog 8530 serial controller chip (SCC) instead of the lower-cost and more common UART to provide serial port connections. The SCC cost about $ 5 more than a UART, but offered much higher speeds of up to 250 kilobits per second (or higher with additional hardware) and internally supported

1016-493: A 10BASE-T port in addition to AAUI. The PowerBook 3400c and lower-end Power Macs also added 10BASE-T. The Power Macintosh 7300 / 8600 / 9600 were the final Macs to include AAUI, and 10BASE-T became universal starting with the Power Macintosh G3 and PowerBook G3 . From the beginning of AppleTalk, users wanted to connect the Macintosh to TCP/IP network environments. In 1984, Bill Croft at Stanford University pioneered

1143-545: A Defense Department teleconferencing application. This demonstrated the feasibility of employing TCP/IP LANs to interconnect Worldwide Military Command and Control System (WWMCCS) computers at command centers throughout the United States. However, WWMCCS was superseded by the Global Command and Control System (GCCS) before that could happen. During the same period, Unix workstations were using TCP/IP networking. Although

1270-509: A PC expansion card that ran up to 1.7 Mbit/s when talking to other Dayna PC cards. Several other systems also existed with even higher performance, but these often required special cabling that was incompatible with LocalTalk/PhoneNet, and also required patches to the networking stack that often caused problems. As Apple expanded into more commercial and education markets, they needed to integrate AppleTalk into existing network installations. Many of these organisations had already invested in

1397-414: A bit mask indicating which of the response packets it received, so the responder could retransmit the remainder. ATP could operate in either "at-least-once" mode or "exactly-once" mode. Exactly-once mode was essential for operations which were not idempotent ; in this mode, the responder kept a copy of the response buffers in memory until successful receipt of a release packet from the requestor, or until

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1524-515: A buffer on the switch in its entirety, its frame check sequence verified and only then the packet is forwarded. In modern network equipment, this process is typically done using application-specific integrated circuits allowing packets to be forwarded at wire speed . When a twisted pair or fiber link segment is used and neither end is connected to a repeater, full-duplex Ethernet becomes possible over that segment. In full-duplex mode, both devices can transmit and receive to and from each other at

1651-506: A coaxial cable 0.375 inches (9.5 mm) in diameter, later called thick Ethernet or thicknet . Its successor, 10BASE2 , called thin Ethernet or thinnet , used the RG-58 coaxial cable. The emphasis was on making installation of the cable easier and less costly. Since all communication happens on the same wire, any information sent by one computer is received by all, even if that information

1778-461: A different type), the operating system included a new Network control panel that allowed the user to select which physical connection to use for networking (from "Built-in" or "EtherTalk"). At introduction, Ethernet interface cards were available from 3Com and Kinetics that plugged into a Nubus slot in the machine. The new networking stack also expanded the system to allow a full 255 nodes per LAN. With EtherTalk's release, AppleTalk Personal Network

1905-581: A doubling of network size. Once repeaters with more than two ports became available, it was possible to wire the network in a star topology . Early experiments with star topologies (called Fibernet ) using optical fiber 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 twisted-pair telephone wiring already installed in commercial buildings provided another opportunity to lower costs, expand

2032-484: A family of network protocols and a physical layer. The physical layer had a number of limitations, including a speed of only 230.4 kbit/s, a maximum distance of 1,000 feet (300 m) from end to end, and only 32 nodes per LAN. But as the basic hardware was built into the Mac, adding nodes only cost about $ 50 for the adaptor box. In comparison, Ethernet or Token Ring cards cost hundreds or thousands of dollars. Additionally,

2159-523: A few newly formed companies like Kinetics. By 1987, Ethernet was clearly winning the standards battle over Token Ring, and in the middle of that year, Apple introduced EtherTalk 1.0 , an implementation of the AppleTalk protocol over the Ethernet physical layer. Introduced for the newly released Macintosh II computer, one of Apple's first two Macintoshes with expansion slots (the Macintosh SE had one slot of

2286-500: A free address is found, so for performance purposes the successful address is recorded in NVRAM and used as the default address in the future. This means that in most real-world setups where machines are added a few at a time, only one or two tries are needed before the address effectively becomes constant. The AppleTalk Data Stream Protocol (ADSP) was a comparatively late addition to the AppleTalk protocol suite, done when it became clear that

2413-738: A full introduction at the target price of $ 500 for plug-in AppleNet cards for the Lisa and the Apple II . At that time, early LAN systems were just coming to market, including Ethernet , Token Ring , Econet , and ARCNET . This was a topic of major commercial effort at the time, dominating shows like the National Computer Conference (NCC) in Anaheim in May 1983. All of the systems were jockeying for position in

2540-536: A greater number of nodes, and longer link distances, but retains much backward compatibility . Over time, Ethernet has largely replaced competing wired LAN technologies such as Token Ring , FDDI and ARCNET . The original 10BASE5 Ethernet uses a thick coaxial cable as a shared medium . This was largely superseded by 10BASE2 , which used a thinner and more flexible cable that was both cheaper and easier to use. More modern Ethernet variants use twisted pair and fiber optic links in conjunction with switches . Over

2667-528: A loop-free logical topology using the SPB protocol or the older STP on the network switches. 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. AppleTalk AppleTalk is a discontinued proprietary suite of networking protocols developed by Apple Computer for their Macintosh computers . AppleTalk includes

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2794-482: A name. The NBP lists were examined and displayed by a program known as the Chooser which would display a list of machines on the local network, divided into classes such as file-servers and printers. An AppleTalk address was a four-byte quantity. This consisted of a two-byte network number, a one-byte node number, and a one-byte socket number. Of these, only the network number required any configuration, being obtained from

2921-484: A non-standard connector that was smaller and easier to use, which they called "Apple AUI", or AAUI . FriendlyNet was first introduced on the Quadra 700 and Quadra 900 computers, and used across much of the Mac line for some time. As with LocalTalk, a number of third-party FriendlyNet adaptors quickly appeared. As 10BASE-T became the de facto cabling system for Ethernet, second-generation Power Macintosh machines added

3048-490: A number of basic networking-like protocols like IBM's Bisync . The SCC was chosen because it would allow multiple devices to be attached to the port. Peripherals equipped with similar SCCs could communicate using the built-in protocols, interleaving their data with other peripherals on the same bus. This would eliminate the need for more ports on the back of the machine, and allowed for the elimination of expansion slots for supporting more complex devices. The initial concept

3175-450: A number of features that allow local area networks to be connected with no prior setup or the need for a centralized router or server of any sort. Connected AppleTalk-equipped systems automatically assign addresses, update the distributed namespace, and configure any required inter-networking routing. AppleTalk was released in 1985 and was the primary protocol used by Apple devices through the 1980s and 1990s. Versions were also released for

3302-558: A router. Each node dynamically chose its own node number, according to a protocol (originally the LocalTalk Link Access Protocol LLAP and later, for Ethernet/EtherTalk, the AppleTalk Address Resolution Protocol, AARP) which handled contention between different nodes accidentally choosing the same number. For socket numbers, a few well-known numbers were reserved for special purposes specific to

3429-516: A simple network operating system LAN Manager and its cousin, IBM's LAN Server . None of these enjoyed any lasting success; Netware dominated the personal computer LAN business from early after its introduction in 1983 until the mid-1990s when Microsoft introduced Windows NT . In 1983, TCP/IP was first shown capable of supporting actual defense department applications on a Defense Communication Agency LAN testbed located at Reston, Virginia. The TCP/IP-based LAN successfully supported Telnet , FTP , and

3556-544: A standard for CSMA/CD based on the IEEE 802 draft. Because the DIX proposal was most technically complete and because of the speedy action taken by ECMA which decisively contributed to the conciliation of opinions within IEEE, the IEEE 802.3 CSMA/CD standard was approved in December 1982. IEEE published the 802.3 standard as a draft in 1983 and as a standard in 1985. Approval of Ethernet on

3683-546: A standard part of the Classic Mac OS until 1994, by which time it also supported SNMP and PPP . For some time in the early 1990s, the Mac was a primary client on the rapidly expanding Internet. Among the better-known programs in wide use were Fetch, Eudora, eXodus, NewsWatcher, and the NCSA packages, especially NCSA Mosaic and its offspring, Netscape Navigator . Additionally, a number of server products appeared that allowed

3810-425: A standard. As part of that process Xerox agreed to relinquish their 'Ethernet' trademark. The first standard was published on September 30, 1980, as "The Ethernet, A Local Area Network. Data Link Layer and Physical Layer Specifications". This so-called DIX standard (Digital Intel Xerox) specified 10 Mbit/s Ethernet, with 48-bit destination and source addresses and a global 16-bit Ethertype -type field. Version 2

3937-401: A switching loop. Autonegotiation is the procedure by which two connected devices choose common transmission parameters, e.g. speed and duplex mode. Autonegotiation was initially an optional feature, first introduced with 100BASE-TX (1995 IEEE 802.3u Fast Ethernet standard), and is backward compatible with 10BASE-T. The specification was improved in the 1998 release of IEEE 802.3. Autonegotiation

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4064-504: A timeout elapsed. This way, it could respond to duplicate requests with the same transaction ID by resending the same response data, without performing the actual operation again. The Datagram Delivery Protocol (DDP) was the lowest-level data-link-independent transport protocol. It provided a datagram service with no guarantees of delivery. All application-level protocols, including the infrastructure protocols NBP, RTMP and ZIP, were built on top of DDP. AppleTalk's DDP corresponds closely to

4191-505: A very expensive Ethernet infrastructure and there was no direct way to connect a Macintosh to Ethernet. AppleTalk included a protocol structure for interconnecting AppleTalk subnets and so as a solution, EtherTalk was initially created to use the Ethernet as a backbone between LocalTalk subnets. To accomplish this, organizations would need to purchase a LocalTalk-to-Ethernet bridge and Apple left it to third parties to produce these products. A number of companies responded, including Hayes and

4318-489: A wide variety of communications products under development, and many of these were announced along with AppleTalk Phase II. These included updates to EtherTalk and TokenTalk, AppleTalk software and LocalTalk hardware for the IBM PC , EtherTalk for Apple's A/UX operating system allowing it to use LaserWriters and other network resources, and the Mac X.25 and MacX products. Ethernet had become almost universal by 1990, and it

4445-494: A wide variety of other network devices such as firewalls , load balancers , and network intrusion detection . Advanced LANs are characterized by their use of redundant links with switches using the spanning tree protocol to prevent loops, their ability to manage differing traffic types via quality of service (QoS), and their ability to segregate traffic with VLANs . At the higher network layers, protocols such as NetBIOS , IPX/SPX , AppleTalk and others were once common, but

4572-530: Is commonly carried over Ethernet and so it is considered one of the key technologies that make up the Internet . Ethernet was developed at Xerox PARC between 1973 and 1974 as a means to allow Alto computers to communicate with each other. It was inspired by ALOHAnet , which Robert Metcalfe had studied as part of his PhD dissertation and was originally called the Alto Aloha Network. Metcalfe's idea

4699-407: Is either dropped or forwarded to another segment. This reduces the forwarding latency. One drawback of this method is that it does not readily allow a mixture of different link speeds. Another is that packets that have been corrupted are still propagated through the network. The eventual remedy for this was a return to the original store and forward approach of bridging, where the packet is read into

4826-433: Is in turn connected to the cable (with thin Ethernet the transceiver is usually 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 10BASE5 implementation used

4953-476: Is intended for just one destination. The network interface card interrupts the CPU 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

5080-409: Is mandatory for 1000BASE-T and faster. A switching loop or bridge loop occurs in computer networks when there is more than one Layer 2 ( OSI model ) path between two endpoints (e.g. multiple connections between two network switches or two ports on the same switch connected to each other). The loop creates broadcast storms as broadcasts and multicasts are forwarded by switches out every port ,

5207-616: Is now used to interconnect appliances and other personal devices . As Industrial Ethernet 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. In February 1980, the Institute of Electrical and Electronics Engineers (IEEE) started project 802 to standardize local area networks (LAN). The DIX group with Gary Robinson (DEC), Phil Arst (Intel), and Bob Printis (Xerox) submitted

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5334-400: Is provided, one is picked at random from the "base subnet", 0. It then broadcasts another packet saying "I am selecting this address", and then waits to see if anyone else on the network complains. If another machine has that address, the newly connecting machine will pick another address, and keep trying until it finds a free one. On a network with many machines it may take several tries before

5461-436: 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,

5588-539: Is still the basis of most commercial LANs today. While optical fiber cable is common for links between network switches , use of fiber to the desktop is rare. In a wireless LAN , users have unrestricted movement within the coverage area. Wireless networks have become popular in residences and small businesses, because of their ease of installation. Most wireless LANs use Wi-Fi as wireless adapters are typically integrated into smartphones , tablet computers and laptops . Guests are often offered Internet access via

5715-412: Is used by the operating system on the receiving station to select the appropriate protocol module (e.g., an Internet Protocol version such as IPv4 ). Ethernet frames are said to be self-identifying , because of the EtherType field. 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

5842-518: The 10BASE-T standard introduced a full duplex mode of operation which became common with Fast Ethernet and the de facto standard with Gigabit Ethernet . In full duplex, switch and station can send and receive simultaneously, and therefore modern Ethernets are completely collision-free. For signal degradation and timing reasons, coaxial Ethernet segments have a restricted size. Somewhat larger networks can be built by using an Ethernet repeater . Early repeaters had only two ports, allowing, at most,

5969-452: The Acorn Atom and Acorn System 2 / 3 / 4 computers in 1981. In the 1980s, several token ring network implementations for LANs were developed. IBM released their own implementation of token ring in 1985, It ran at 4  Mbit/s . IBM claimed that their token ring systems were superior to Ethernet, especially under load, but these claims were debated. IBM's implementation of token ring was

6096-702: The Electronic voting systems for the European Parliament was the first installation of a LAN connecting hundreds (420) of microprocessor-controlled voting terminals to a polling/selecting central unit with a multidrop bus with Master/slave (technology) arbitration. The development and proliferation of personal computers using the CP/M operating system in the late 1970s, and later DOS -based systems starting in 1981, meant that many sites grew to dozens or even hundreds of computers. The initial driving force for networking

6223-656: The IBM PC and compatibles and the Apple IIGS . AppleTalk support was also available in most networked printers (especially laser printers ), some file servers , and a number of routers . The rise of TCP/IP during the 1990s led to a reimplementation of most of these types of support on that protocol, and AppleTalk became unsupported as of the release of Mac OS X v10.6 in 2009. Many of AppleTalk's more advanced autoconfiguration features have since been introduced in Bonjour , while Universal Plug and Play serves similar needs. After

6350-404: The Internet protocol suite (TCP/IP) has prevailed as the standard of choice. LANs can maintain connections with other LANs via leased lines, leased services, or across the Internet using virtual private network technologies. Depending on how the connections are established and secured, and the distance involved, such linked LANs may also be classified as a metropolitan area network (MAN) or

6477-559: The Name Binding Protocol ( NBP ) was a dynamic system for mapping network addresses to user-readable names. Although systems similar to AARP existed in other systems, Banyan VINES for instance. Beginning about 2002 Rendezvous (the combination of DNS-based service discovery , Multicast DNS , and link-local addressing ) provided capabilities and usability using IP that were similar to those of AppleTalk. Both AARP and NBP had defined ways to allow "controller" devices to override

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6604-661: The OSI model of protocol layering. Unlike most of the early LAN systems, AppleTalk was not built using the archetypal Xerox XNS system. The intended target was not Ethernet, and it did not have 48-bit addresses to route. Nevertheless, many portions of the AppleTalk system have direct analogs in XNS. One key differentiation for AppleTalk was it contained two protocols aimed at making the system completely self-configuring. The AppleTalk address resolution protocol ( AARP ) allowed AppleTalk hosts to automatically generate their own network addresses, and

6731-500: The OSI model , Ethernet provides services up to and including the data link layer . The 48-bit MAC address was adopted by other IEEE 802 networking standards, including IEEE 802.11 ( Wi-Fi ), as well as by FDDI . EtherType values are also used in Subnetwork Access Protocol (SNAP) headers. Ethernet is widely used in homes and industry, and interworks well with wireless Wi-Fi technologies. The Internet Protocol

6858-569: The PowerPC -based machines. This led to the Open Transport efforts, which re-implemented both MacTCP and AppleTalk on an entirely new code base adapted from the Unix standard STREAMS . Early versions had problems and did not become stable for some time. By that point, Apple was deep in their ultimately doomed Copland efforts. With the purchase of NeXT and subsequent development of Mac OS X , AppleTalk

6985-573: The Spanning Tree Protocol (STP) to maintain a loop-free, meshed network, allowing physical loops for redundancy (STP) or load-balancing (SPB). Shortest Path Bridging includes the use of the link-state routing protocol IS-IS to allow larger networks with shortest path routes between devices. Advanced networking features also ensure port security, provide protection features such as MAC lockdown and broadcast radiation filtering, use VLANs to keep different classes of users separate while using

7112-439: The AppleTalk model. The AppleTalk Address Resolution Protocol (AARP) resolves AppleTalk addresses to link layer addresses. It is functionally equivalent to ARP and obtains address resolution by a method very similar to ARP. AARP is a fairly simple system. When powered on, an AppleTalk machine broadcasts an AARP probe packet asking for a network address, intending to hear back from controllers such as routers. If no address

7239-434: The AppleTalk protocol itself. Apart from these, all application-level protocols were expected to use dynamically assigned socket numbers at both the client and server end. Because of this dynamism, users could not be expected to access services by specifying their address. Instead, all services had names which, being chosen by humans, could be expected to be meaningful to users, and also could be sufficiently long to minimize

7366-411: The Ethernet and LocalTalk compatibility problem: Networks with new and old Macs needed some way to communicate with each other. This could be as simple as a network of Ethernet Mac II's trying to talk to a LaserWriter that only connected to LocalTalk. Apple initially relied on the aforementioned LocalTalk-to-Ethernet bridge products, but contrary to Apple's belief that these would be low-volume products, by

7493-484: The LAN was observed. This is in contrast with token passing 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

7620-463: The Mac to host Internet content. Through this period, Macs had about 2 to 3 times as many clients connected to the Internet as any other platform, despite the relatively small overall microcomputer market share. As the world quickly moved to IP for both LAN and WAN uses, Apple was faced with maintaining two increasingly outdated code bases on an ever-wider group of machines as well as the introduction of

7747-457: The Mac, LaserWriter, and a file server system which would become the Macintosh Office . By late 1983 it was clear that IBM's Token Ring would not be ready in time for the launch of the Mac, and might miss the launch of these other products as well. In the end, Token Ring would not ship until October 1985. Jobs' earlier question to Sidhu had already sparked a number of ideas. When AppleNet

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7874-481: The Macintosh HFS filesystem. AFP is still in use in macOS, even though most other AppleTalk protocols have been deprecated. The AppleTalk Session Protocol (ASP) was an intermediate protocol, built on top of AppleTalk Transaction Protocol (ATP), which in turn was the foundation of AFP. It provided basic services for requesting responses to arbitrary commands and performing out-of-band status queries. It also allowed

8001-531: The Network layer of the Open Systems Interconnection ( OSI ) communication model. The Name Binding Protocol (NBP) was a dynamic, distributed system for managing AppleTalk names. When a service started up on a machine, it registered a name for itself as chosen by a human administrator. At this point, NBP provided a system for checking that no other machine had already registered the same name. Later, when

8128-512: The adaptors were designed to be "self-terminating", meaning that nodes at the end of the network could simply leave their last connector unconnected. There was no need for the wires to be connected back together into a loop, nor the need for hubs or other devices. The system was designed for future expansion; the addressing system allowed for expansion to 255 nodes in a LAN (although only 32 could be used at that time), and by using "bridges" (which came to be known as "routers", although technically not

8255-460: The advent of Novell NetWare which provided even-handed support for dozens of competing card and cable types, and a much more sophisticated operating system than most of its competitors. Of the competitors to NetWare, only Banyan Vines had comparable technical strengths, but Banyan never gained a secure base. 3Com produced 3+Share and Microsoft produced MS-Net . These then formed the basis for collaboration between Microsoft and 3Com to create

8382-566: The basis of the IEEE 802.5 standard. A 16 Mbit/s version of Token Ring was standardized by the 802.5 working group in 1989. IBM had market dominance over Token Ring, for example, in 1990, IBM equipment was the most widely used for Token Ring networks. Fiber Distributed Data Interface (FDDI), a LAN standard, was considered an attractive campus backbone network technology in the early to mid 1990s since existing Ethernet networks only offered 10 Mbit/s data rates and Token Ring networks only offered 4 Mbit/s or 16 Mbit/s rates. Thus it

8509-650: The benches of the European Parliament Hemicycles in Strasbourg and Luxembourg. Early Ethernet ( 10BASE-5 and 10BASE-2 ) used coaxial cable . Shielded twisted pair was used in IBM's Token Ring LAN implementation. In 1984, StarLAN showed the potential of simple unshielded twisted pair by using category 3 cable —the same cable used for telephone systems. This led to the development of 10BASE-T (and its twisted-pair successors ) and structured cabling which

8636-453: The chance of conflicts. As NBP names translated to an address, which included a socket number as well as a node number, a name in AppleTalk mapped directly to a service being provided by a machine, which was entirely separate from the name of the machine itself. Thus, services could be moved to a different machine and, so long as they kept the same service name, there was no need for users to do anything different in order to continue accessing

8763-621: 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 , with rates up to 1.6  Tbit/s under development. The Ethernet standards include several wiring and signaling variants of the OSI physical layer . Systems communicating over Ethernet divide a stream of data into shorter pieces called frames . Each frame contains source and destination addresses, and error-checking data so that damaged frames can be detected and discarded; most often, higher-layer protocols trigger retransmission of lost frames. Per

8890-440: The default mechanisms. The concept was to allow routers to provide the information or "hardwire" the system to known addresses and names. On larger networks where AARP could cause problems as new nodes searched for free addresses, the addition of a router could reduce "chattiness." Together AARP and NBP made AppleTalk an easy-to-use networking system. New machines were added to the network by plugging them in and optionally giving them

9017-455: 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. An EtherType field in each frame

9144-510: The development of IP packets encapsulated in DDP as part of the SEAGATE (Stanford Ethernet–AppleTalk Gateway) project. SEAGATE was commercialized by Kinetics in their LocalTalk-to-Ethernet bridge as an additional routing option. A few years later, MacIP was separated from the SEAGATE code and became the de facto method for IP packets to be routed over LocalTalk networks. By 1986, Columbia University released

9271-537: The devices through the Chooser . AppleTalk was so easy to use that ad hoc networks tended to appear whenever multiple Macs were in the same room. Apple would later use this in an advertisement showing a network being created between two seats in an airplane. A thriving third-party market for AppleTalk devices developed over the next few years. One particularly notable example was an alternate adaptor designed by BMUG and commercialised by Farallon as PhoneNET in 1987. This

9398-564: The elimination of the chaining limits inherent in non-switched Ethernet have made switched Ethernet the dominant network technology. 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 switching loops , broadcast radiation , and multicast traffic. Advanced networking features in switches use Shortest Path Bridging (SPB) or

9525-482: The emerging office communication market, including Siemens' support for the international standardization of Ethernet (April 10, 1981). Ingrid Fromm, Siemens' representative to IEEE 802, quickly achieved broader support for Ethernet beyond IEEE by the establishment of a competing Task Group "Local Networks" within the European standards body ECMA TC24. In March 1982, ECMA TC24 with its corporate members reached an agreement on

9652-531: The end of 1987, 130,000 such networks were in use. AppleTalk was at that time the most used networking system in the world, with over three times the installations of any other vendor. 1987 also marked the introduction of the AppleShare product, a dedicated file server that ran on any Mac with 512 kB of RAM or more. A common AppleShare machine was the Mac Plus with an external SCSI hard drive . AppleShare

9779-482: The entire networking stack required only about 6 kB of RAM, allowing it to run on any Mac. The relatively slow speed of AppleTalk allowed further reductions in cost. Instead of using RS-422 's balanced transmit and receive circuits, the AppleTalk cabling used a single common electrical ground , which limited speeds to about 500 kbit/s, but allowed one conductor to be removed. This meant that common three-conductor cables could be used for wiring. Additionally,

9906-449: 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, and the ever-decreasing cost of the hardware needed to support it, by 2004 most manufacturers built Ethernet interfaces directly into PC motherboards , eliminating

10033-474: The external adaptor also included its own clock , and used that to signal the SCC's clock input pins. The best-known such system was Centram's FlashTalk , which ran at 768 kbit/s, and was intended to be used with their TOPS networking system. A similar solution was the 850 kbit/s DaynaTalk , which used a separate box that plugged in between the computer and a normal LocalTalk/PhoneNet box. Dayna also offered

10160-612: The farthest nodes and creates practical limits on how many machines can communicate on an Ethernet network. 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 work somewhat like Ethernet repeaters, passing all traffic between segments. By observing

10287-607: The first version of the Columbia AppleTalk Package (CAP) that allowed higher integration of Unix, TCP/IP, and AppleTalk environments. In 1988, Apple released MacTCP , a system that allowed the Mac to support TCP/IP on machines with suitable Ethernet hardware. However, this left many universities with the problem of supporting IP on their many LocalTalk-equipped Macs. It was soon common to include MacIP support in LocalTalk-to-Ethernet bridges. MacTCP would not become

10414-504: The group was split into three subgroups, and standardization proceeded separately for each proposal. Delays in the standards process put at risk the market introduction of the Xerox Star workstation and 3Com's Ethernet LAN products. With such business implications in mind, David Liddle (General Manager, Xerox Office Systems) and Metcalfe (3Com) strongly supported a proposal of Fritz Röscheisen ( Siemens Private Networks) for an alliance in

10541-548: The growth of their "Octopus" network gave a good indication of the situation. A number of experimental and early commercial LAN technologies were developed in the 1970s. Ethernet was developed at Xerox PARC between 1973 and 1974. Cambridge Ring was developed at Cambridge University starting in 1974. ARCNET was developed by Datapoint Corporation in 1976 and announced in 1977. It had the first commercial installation in December 1977 at Chase Manhattan Bank in New York. In 1979,

10668-439: 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 StarLAN at 1 Mbit/s in the mid-1980s. In 1987 SynOptics introduced the first twisted-pair Ethernet at 10 Mbit/s in a star-wired cabling topology with a central hub, later called LattisNet . These evolved into 10BASE-T, which

10795-510: The international level was achieved by a similar, cross- partisan action with Fromm as the liaison officer working to integrate with International Electrotechnical Commission (IEC) Technical Committee 83 and International Organization for Standardization (ISO) Technical Committee 97 Sub Committee 6. The ISO 8802-3 standard was published in 1989. Ethernet has evolved to include higher bandwidth, improved medium access control methods, and different physical media. The multidrop coaxial cable

10922-540: 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. In the 1980s, IBM's own PC Network product competed with Ethernet for the PC, and through the 1980s, LAN hardware, in general, was not common on PCs. However, in the mid to late 1980s, PC networking did become popular in offices and schools for printer and fileserver sharing, and among

11049-399: The length of the payload. The middle section of the frame consists of payload data including any headers for other protocols (for example, Internet Protocol) carried in the frame. The frame ends with a 32-bit cyclic redundancy check , which is used to detect corruption of data in transit . Notably, Ethernet packets have no time-to-live field , leading to possible problems in the presence of

11176-631: The many diverse competing LAN technologies of that decade, Ethernet was one of the most popular. Parallel port based Ethernet adapters were produced for a time, with drivers for DOS and Windows. By the early 1990s, Ethernet became so prevalent that Ethernet ports began to appear on some PCs and most workstations . This process was greatly sped up with the introduction of 10BASE-T and its relatively small modular connector , 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

11303-708: The market, but even at this time, Ethernet's widespread acceptance suggested it was to become a de facto standard. It was at this show that Steve Jobs asked Gursharan Sidhu a seemingly innocuous question: "Why has networking not caught on?" Four months later, in October, AppleNet was cancelled. At the time, they announced that "Apple realized that it's not in the business to create a networking system. We built and used AppleNet in-house, but we realized that if we had shipped it, we would have seen new standards coming up." In January, Jobs announced that they would instead be supporting IBM 's Token Ring, which he expected to come out in

11430-401: The mixing of speeds, both of which are critical to the incremental deployment of faster Ethernet variants. In 1989, Motorola Codex introduced their 6310 EtherSpan, and Kalpana introduced their EtherSwitch; these were examples of the first commercial Ethernet switches. Early switches such as this used cut-through switching where only the header of the incoming packet is examined before it

11557-470: The need for a separate network card. 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 Luminiferous aether in 19th-century physics, and it was from this reference that the name Ethernet

11684-470: 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 jam signal 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

11811-427: The next computer upstream and downstream. Adaptors for Apple II and Apple III were also announced. Apple also announced that an AppleBus network could be attached to, and would appear to be a single node within, a Token Ring system. Details of how this would work were sketchy. Just prior to its release in early 1985, AppleBus was renamed AppleTalk . Initially marketed as AppleTalk Personal Network , it comprised

11938-625: The now-ubiquitous twisted pair with 10BASE-T. 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 NIC in March 1981, and that year started selling adapters for PDP-11s and VAXes , as well as Multibus -based Intel and Sun Microsystems computers. This was followed quickly by DEC's Unibus 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

12065-450: 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 ARP spoofing and MAC flooding . The bandwidth advantages, the improved isolation of devices from each other, the ability to easily mix different speeds of devices and

12192-504: The release of the Apple Lisa computer in January 1983, Apple invested considerable effort in the development of a local area networking (LAN) system for the machines. Known as AppleNet , it was based on the seminal Xerox XNS protocol stack but running on a custom 1 Mbit/s coaxial cable system rather than Xerox's 2.94 Mbit/s Ethernet . AppleNet was announced early in 1983 with

12319-411: The repeater is limited to that of a single link, and all links must operate at the same speed. While repeaters can isolate some aspects of Ethernet segments , such as cable breakages, they still forward all traffic to all Ethernet devices. The entire network is one collision domain , and all hosts have to be able to detect collisions anywhere on the network. This limits the number of repeaters between

12446-549: The same physical infrastructure, employ multilayer switching to route between different classes, and use link aggregation to add bandwidth to overloaded links and to provide some redundancy. In 2016, Ethernet replaced InfiniBand as the most popular system interconnect of TOP500 supercomputers. The Ethernet physical layer evolved over a considerable time span and encompasses coaxial, twisted pair and fiber-optic physical media interfaces, with speeds from 1 Mbit/s to 400 Gbit/s . The first introduction of twisted-pair CSMA/CD

12573-482: 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 for Fast Ethernet). 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 constraints of collision detection. Since packets are typically delivered only to

12700-512: 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 Xerox 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

12827-412: The same) one could interconnect LANs into larger collections. "Zones" allowed devices to be addressed within a bridge-connected internet. Additionally, AppleTalk was designed from the start to allow use with any potential underlying physical link, and within a few years, the physical layer would be renamed LocalTalk , so as to differentiate it from the AppleTalk protocols. The main advantage of AppleTalk

12954-621: The server to send asynchronous attention messages to the client. The AppleTalk Transaction Protocol (ATP) was the original reliable transport-level protocol for AppleTalk, built on top of DDP. At the time it was being developed, a full, reliable connection-oriented protocol like TCP was considered to be too expensive to implement for most of the intended uses of AppleTalk. Thus, ATP was a simple request/response exchange, with no need to set up or tear down connections. An ATP request packet could be answered by up to eight response packets. The requestor then sent an acknowledgement packet containing

13081-409: The service is moved to a different machine. This can be mitigated somewhat by insistence on using CNAME records indicating service rather than actual machine names to refer to the service, but there is no way of guaranteeing that users will follow such a convention. Some newer protocols, such as Kerberos and Active Directory use DNS SRV records to identify services by name, which is much closer to

13208-475: The service. And the same machine could host any number of instances of services of the same type, without any network connection conflicts. Contrast this with A records in the DNS , in which a name translates to a machine's address, not including the port number that might be providing a service. Thus, if people are accustomed to using a particular machine name to access a particular service, their access will break when

13335-413: The so-called Blue Book CSMA/CD specification as a candidate for the LAN specification. In addition to CSMA/CD, Token Ring (supported by IBM) and Token Bus (selected and henceforward supported by General Motors ) were also considered as candidates for a LAN standard. Competing proposals and broad interest in the initiative led to strong disagreement over which technology to standardize. In December 1980,

13462-411: 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. Broadcast traffic is still forwarded to all network segments. Bridges also overcome the limits on total segments between two hosts and allow

13589-478: The switch or switches will repeatedly rebroadcast the broadcast messages flooding the network. Since the Layer 2 header does not support a time to live (TTL) value, if a frame is sent into a looped topology, it can loop forever. A physical topology that contains switching or bridge loops is attractive for redundancy reasons, yet a switched network must not have loops. The solution is to allow physical loops, but create

13716-529: The system was deployed at PARC, Metcalfe and Boggs published a seminal paper. Ron Crane , Yogen Dalal , Robert Garner, Hal Murray, Roy Ogus, Dave Redell and John Shoch facilitated the upgrade from the original 2.94 Mbit/s protocol to the 10 Mbit/s protocol, which was released to the market in 1980. Metcalfe left Xerox in June 1979 to form 3Com . He convinced Digital Equipment Corporation (DEC), Intel , and Xerox to work together to promote Ethernet as

13843-405: The time the Mac was released, the basic concepts had been outlined, and some of the low-level protocols were on their way to completion. Sidhu mentioned the work to Belleville only two hours after the Mac was announced. The "new" AppleBus was announced in early 1984, allowing direct connection from the Mac or Lisa through a small box that is plugged into the serial port and connected via cables to

13970-470: The workstation market segment is now much reduced, the technologies developed in the area continue to be influential on the Internet and in all forms of networking—and the TCP/IP protocol has replaced IPX , AppleTalk , NBF , and other protocols used by the early PC LANs. Econet was Acorn Computers's low-cost local area network system, intended for use by schools and small businesses. It was first developed for

14097-766: Was StarLAN , 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 through 10GBASE-T. The most common forms used are 10BASE-T, 100BASE-TX, and 1000BASE-T . All three use twisted-pair cables and 8P8C modular connectors . They run at 10 Mbit/s , 100 Mbit/s , and 1 Gbit/s , respectively. Fiber optic variants of Ethernet (that commonly use SFP modules ) are also very popular in larger networks, offering high performance, better electrical isolation and longer distance (tens of kilometers with some versions). In general, network protocol stack software will work similarly on all varieties. In IEEE 802.3,

14224-519: Was a relatively high-speed choice of that era, with speeds such as 100 Mbit/s. By 1994, vendors included Cisco Systems , National Semiconductor , Network Peripherals, SysKonnect (acquired by Marvell Technology Group ), and 3Com . FDDI installations have largely been replaced by Ethernet deployments. In 1979, the Electronic voting systems for the European Parliament was using 10 kilometers of simple unshielded twisted pair category 3 cable —the same cable used for telephone systems—installed inside

14351-455: Was cancelled in October, Sidhu led an effort to develop a new networking system based on the AppleBus hardware. This new system would not have to conform to any existing preconceptions, and was designed to be worthy of the Mac – a system that was user-installable and required no configuration or fixed network addresses – in short, a true plug-and-play network. Considerable effort was needed, but by

14478-435: Was derived. Original Ethernet's shared coaxial cable (the shared medium) traversed a building or campus to every attached machine. A scheme known as carrier-sense multiple access with collision detection (CSMA/CD) governed the way the computers shared the channel. This scheme was simpler than competing Token Ring or Token Bus technologies. Computers are connected to an Attachment Unit Interface (AUI) transceiver , which

14605-446: 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

14732-486: Was essentially a replacement for Apple's connector that had conventional phone jacks instead of Apple's round connectors. PhoneNet allowed AppleTalk networks to be connected together using normal telephone wires, and with very little extra work, could run analog phones and AppleTalk on a single four-conductor phone cable. Other companies took advantage of the SCC's ability to read external clocks in order to support higher transmission speeds, up to 1 Mbit/s. In these systems,

14859-549: Was essentially to limit the Aloha-like signals inside a cable, instead of broadcasting into the air. The idea was first documented in a memo that Metcalfe wrote on May 22, 1973, where he named it after the luminiferous aether once postulated to exist as an "omnipresent, completely passive medium for the propagation of electromagnetic waves." In 1975, Xerox filed a patent application listing Metcalfe, David Boggs , Chuck Thacker , and Butler Lampson as inventors. In 1976, after

14986-677: Was finally removed from the macOS line in Mac OS X v10.6 in 2009. However, the loss of AppleTalk did not reduce the desire for networking solutions that combined its ease of use with IP routing. Apple has led the development of many such efforts, from the introduction of the AirPort router to the development of the zero-configuration networking system and their implementation of it, Rendezvous, later renamed Bonjour . As of 2020, AppleTalk support has been completely removed from legacy support with macOS 11 Big Sur. The AppleTalk design rigorously followed

15113-501: Was known as AppleBus , envisioning a system controlled by the host Macintosh polling "dumb" devices in a fashion similar to the modern Universal Serial Bus . The Macintosh team had already begun work on what would become the LaserWriter and had considered a number of other options to answer the question of how to share these expensive machines and other resources. A series of memos from Bob Belleville clarified these concepts, outlining

15240-463: Was published in November 1982 and defines what has become known as Ethernet II . Formal standardization efforts proceeded at the same time and resulted in the publication of IEEE 802.3 on June 23, 1983. Ethernet initially competed with Token Ring and other proprietary protocols . Ethernet was able to adapt to market needs, and with 10BASE2 shift to inexpensive thin coaxial cable, and from 1990 to

15367-431: Was renamed LocalTalk , the name it would be known under for the bulk of its life. Token Ring would later be supported with a similar TokenTalk product, which used the same Network control panel and underlying software. Over time, many third-party companies would introduce compatible Ethernet and Token Ring cards that used these same drivers. The appearance of a Macintosh with a direct Ethernet connection also magnified

15494-407: Was replaced with physical point-to-point links connected by Ethernet repeaters or switches . Ethernet stations communicate by sending each other data packets : blocks of data individually sent and delivered. As with other IEEE 802 LANs, adapters come programmed with globally unique 48-bit MAC address so that each Ethernet station has a unique address. The MAC addresses are used to specify both

15621-440: Was strictly a legacy system. Support was added to Mac OS X in order to provide support for a large number of existing AppleTalk devices, notably laser printers and file shares, but alternate connection solutions common in this era, notably USB for printers, limited their demand. As Apple abandoned many of these product categories, and all new systems were based on IP, AppleTalk became less and less common. AppleTalk support

15748-401: Was that it was completely maintenance-free. To join a device to a network, a user simply plugged the adaptor into the machine, then connected a cable from it to any free port on any other adaptor. The AppleTalk network stack negotiated a network address, assigned the computer a human-readable name, and compiled a list of the names and types of other machines on the network so the user could browse

15875-639: Was the #3 network operating system in the late 1980s, behind Novell NetWare and Microsoft's MS-Net . AppleShare was effectively the replacement for the failed Macintosh Office efforts, which had been based on a dedicated file server device. A significant re-design was released in 1989 as AppleTalk Phase II . In many ways, Phase II can be considered an effort to make the earlier version (never called Phase I) more generic. LANs could now support more than 255 nodes, and zones were no longer associated with physical networks but were entirely virtual constructs used simply to organize nodes. For instance, one could now make

16002-416: Was time to build Ethernet into Macs direct from the factory. However, the physical wiring used by these networks was not yet completely standardized. Apple solved this problem using a single port on the back of the computer into which the user could plug an adaptor for any given cabling system. This FriendlyNet system was based on the industry-standard Attachment Unit Interface or AUI, but deliberately chose

16129-582: Was to share storage and printers , both of which were expensive at the time. There was much enthusiasm for the concept, and for several years, from about 1983 onward, computer industry pundits habitually declared the coming year to be, "The year of the LAN". In practice, the concept was marred by the proliferation of incompatible physical layer and network protocol implementations, and a plethora of methods of sharing resources. Typically, each vendor would have its own type of network card, cabling, protocol, and network operating system . A solution appeared with

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