Ethernet physical layer
Encyclopedia
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| A standard 8P8C (often called RJ45) connector Electrical connector An electrical connector is an electro-mechanical device for joining electrical circuits as an interface using a mechanical assembly. The connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or... used most commonly on cat5 cable Category 5 cable Category 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors... , one of the types of cabling used in Ethernet networks |
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| Standard | IEEE 802.3 (2002 onwards) |
|---|---|
| Physical media | Coaxial cable, twisted pair, optical fiber |
| Network topology | Point-to-point, star, bus |
| Major variants | 10BASE-T 10BASE-T Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Other Ethernet cable standards employ coaxial cable or optical fiber. Early versions developed in the 1980s included StarLAN followed by 10BASE-T. By the 1990s, fast, inexpensive... , 10BASE2 10BASE2 10BASE2 is a variant of Ethernet that uses thin coaxial cable , terminated with BNC connectors... , 10BASE5 10BASE5 10BASE5 was the original commercially available variant of Ethernet.For its physical layer it used cable similar to RG-8/U coaxial cable but with extra braided shielding. This is a stiff, diameter cable with an impedance of 50 ohms , a solid center conductor, a foam insulating filler, a shielding... , 100BASE-TX, 100BASE-FX, 100BASE-T, 1000BASE-T, 1000BASE-SX |
| Maximum distance | 100 metres (328 ft) over twisted pair, up to 100 km over optical fiber |
| Mode of operation | Differential (Balanced) |
| Maximum bit rate | 3 Mbit/s to 100 Gbit/s |
| Voltage levels | +/- 2.5V (over twisted pair) |
| Available signals | Tx+, Tx-, Rx+, Rx- |
| Common connector types | 8P8C, LC, SC, ST |
The Ethernet physical layer is the physical layer
Physical layer
The physical layer or layer 1 is the first and lowest layer in the seven-layer OSI model of computer networking. The implementation of this layer is often termed PHY....
component of the Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
family of computer network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
standards.
The Ethernet physical layer evolved over a considerable time span and encompasses quite a few physical media interfaces and several magnitude
Magnitude (mathematics)
The magnitude of an object in mathematics is its size: a property by which it can be compared as larger or smaller than other objects of the same kind; in technical terms, an ordering of the class of objects to which it belongs....
s of speed. The speed ranges from 1 Mbit/s to 100 Gbit/s while the physical medium can range from bulky coaxial cable
Coaxial cable
Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
to twisted pair
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
to optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
. In general, network protocol stack
Protocol stack
The protocol stack is an implementation of a computer networking protocol suite. The terms are often used interchangeably. Strictly speaking, the suite is the definition of the protocols, and the stack is the software implementation of them....
software will work similarly on all physical layers.
10 Gigabit Ethernet
10 Gigabit Ethernet
The 10 gigabit Ethernet computer networking standard was first published in 2002. It defines a version of Ethernet with a nominal data rate of 10 Gbit/s , ten times faster than gigabit Ethernet.10 gigabit Ethernet defines only full duplex point to point links which are generally connected by...
is becoming more popular in both enterprise and carrier networks, with 40 Gbit/s and 100 Gbit/s Ethernet
100 Gigabit Ethernet
40 Gigabit Ethernet, or 40GbE, and 100 Gigabit Ethernet, or 100GbE, are high-speed computer network standards developed by the Institute of Electrical and Electronics Engineers . They support sending Ethernet frames at 40 and 100 gigabits per second over multiple 10 Gbit/s or 25 Gbit/s lanes...
ratified. Higher speeds are under development. Metcalfe
Robert Metcalfe
Robert Melancton Metcalfe is an electrical engineer from the United States who co-invented Ethernet, founded 3Com and formulated Metcalfe's Law., he is a general partner of Polaris Venture Partners...
, one of the co-inventors of ethernet, now believes commercial applications using terabit
Terabit
The terabit is a multiple of the unit bit for digital information or computer storage. The prefix tera is defined in the International System of Units as a multiplier of 1012 , and therefore...
Ethernet may occur by 2015 though he says existing Ethernet standards may have to be overthrown to reach terabit Ethernet.
Many Ethernet adapters and switch
Network switch
A network switch or switching hub is a computer networking device that connects network segments.The term commonly refers to a multi-port network bridge that processes and routes data at the data link layer of the OSI model...
ports support multiple speeds, using autonegotiation
Autonegotiation
Autonegotiation is an Ethernet procedure by which two connected devices choose common transmission parameters, such as speed, duplex mode, and flow control. In this process, the connected devices first share their capabilities regarding these parameters and then choose the highest performance...
to set the speed and duplex
Duplex (telecommunications)
A duplex communication system is a system composed of two connected parties or devices that can communicate with one another in both directions. The term multiplexing is used when describing communication between more than two parties or devices....
for the best values supported by both connected devices. If auto-negotiation fails, a multiple speed device will sense the speed used by its partner, but will assume half-duplex. A 10/100 Ethernet port supports 10BASE-T
10BASE-T
Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Other Ethernet cable standards employ coaxial cable or optical fiber. Early versions developed in the 1980s included StarLAN followed by 10BASE-T. By the 1990s, fast, inexpensive...
and 100BASE-TX. A 10/100/1000 Ethernet port supports 10BASE-T
10BASE-T
Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Other Ethernet cable standards employ coaxial cable or optical fiber. Early versions developed in the 1980s included StarLAN followed by 10BASE-T. By the 1990s, fast, inexpensive...
, 100BASE-TX, and 1000BASE-T.
Xerox experimental Ethernet
| Name | Description |
|---|---|
| Experimental Ethernet | The original 2.94 Mbit/s Ethernet implementation had a eight bit addresses and other differences in frame format. Manchester code Manchester code In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time... d on 50 Ω Ohm The ohm is the SI unit of electrical resistance, named after German physicist Georg Simon Ohm.- Definition :The ohm is defined as a resistance between two points of a conductor when a constant potential difference of 1 volt, applied to these points, produces in the conductor a current of 1 ampere,... coaxial cable. |
The following sections provide a brief summary of official Ethernet media types (section numbers from the IEEE 802.3-2008
IEEE 802.3
IEEE 802.3 is a working group and a collection of IEEE standards produced by the working group defining the physical layer and data link layer's media access control of wired Ethernet. This is generally a local area network technology with some wide area network applications...
standard are parenthesized). In addition to these official standards, many vendors have implemented proprietary media types for various reasons—often to support longer distances over fiber optic cabling.
Early implementations
| Name | Standard | Description |
|---|---|---|
| 10BASE5 10BASE5 10BASE5 was the original commercially available variant of Ethernet.For its physical layer it used cable similar to RG-8/U coaxial cable but with extra braided shielding. This is a stiff, diameter cable with an impedance of 50 ohms , a solid center conductor, a foam insulating filler, a shielding... |
802.3 (8) | Original standard uses a single coaxial cable into which you literally tap a connection by drilling into the cable to connect to the core and screen. Largely obsolete, though due to its widespread deployment in the early 1980s, some systems may still be in use. Was known also as Thick-Ethernet. 10 Mbit/s, Manchester code Manchester code In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time... d signaling, copper RG-8X (expensive) coaxial cabling, bus topology with collision detection Collision detection Collision detection typically refers to the computational problem of detecting the intersection of two or more objects. While the topic is most often associated with its use in video games and other physical simulations, it also has applications in robotics... . |
| 10BASE2 10BASE2 10BASE2 is a variant of Ethernet that uses thin coaxial cable , terminated with BNC connectors... |
802.3 (10) | 50 Ω Ohm The ohm is the SI unit of electrical resistance, named after German physicist Georg Simon Ohm.- Definition :The ohm is defined as a resistance between two points of a conductor when a constant potential difference of 1 volt, applied to these points, produces in the conductor a current of 1 ampere,... coaxial cable connects machines together, each machine using a T-adaptor to connect to its NIC. Requires terminators Electrical termination Electrical termination of a signal involves providing a terminator at the end of a wire or cable to prevent an RF signal from being reflected back from the end, causing interference... at each end. For many years during the mid to late 1980 this was the dominant Ethernet standard. Also called Thin Ethernet, ThinNet or Cheapernet. 10 Mbit/s, Manchester code Manchester code In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time... d signaling, copper RG-58 RG-58 RG-58/U is a type of coaxial cable often used for low-power signal and RF connections. The cable has a characteristic impedance of either 50 or 52 Ω. "RG" was originally a unit indicator for bulk RF cable in the U.S. military's Joint Electronics Type Designation System... (cheap) coaxial cabling, bus topology with collision detection. |
| 10BROAD36 10BROAD36 10BROAD36 is an obsolete computer network standard in the Ethernet family. It was developed during the 1980s and specified in IEEE 802.3b-1985.... |
802.3 (11) | An early standard supporting Ethernet over longer distances. It utilized broadband modulation techniques, similar to those employed in cable modem Cable modem A cable modem is a type of network bridge and modem that provides bi-directional data communication via radio frequency channels on a HFC and RFoG infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high... systems, and operated over coaxial cable. 10 Mbit/s, scrambled NRZ Non-return-to-zero In telecommunication, a non-return-to-zero line code is a binary code in which 1's are represented by one significant condition and 0's are represented by some other significant condition , with no other neutral or rest condition. The pulses have more energy than a RZ code... signaling modulated (PSK Phase-shift keying Phase-shift keying is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal .... ) over high frequency carrier, broad bandwidth coaxial cabling, bus topology with collision detection. |
| 1BASE5 | 802.3 (12) | Operated at 1 Mbit/s over twisted pair to an active hub. Although a commercial failure, 1BASE5 defined the architecture for all subsequent Ethernet evolution. Also called StarLAN StarLAN StarLAN was the first implementation of 1 megabit per second Ethernet over twisted pair wiring. It was standardized by the standards association of the Institute of Electrical and Electronics Engineers as 802.3e in 1986, as the 1BASE5 version of Ethernet.-Description:StarLAN was developed by AT&T... . 1 Mbit/s, Manchester code Manchester code In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time... d signaling, copper twisted pair cabling, star topology. |
| StarLAN StarLAN StarLAN was the first implementation of 1 megabit per second Ethernet over twisted pair wiring. It was standardized by the standards association of the Institute of Electrical and Electronics Engineers as 802.3e in 1986, as the 1BASE5 version of Ethernet.-Description:StarLAN was developed by AT&T... 10 |
Proprietary | 10 Mbit/s, Manchester code Manchester code In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time... d signaling, copper twisted pair cabling, star topology - evolved into 10BASE-T |
| LattisNet LattisNet LattisNet was a family of computer networking hardware and software products built and sold by SynOptics Communications during the 1980s... UTP |
Proprietary | 10 Mbit/s, Manchester code Manchester code In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time... d signaling, copper twisted pair cabling, star topology - evolved into 10BASE-T |
| 10BASE‑T | 802.3 (14) | Runs over four wires (two twisted pair Twisted pair Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs... s) on a Category 3 Category 3 cable Category 3 cable, commonly known as Cat 3 or station wire, is an unshielded twisted pair cable designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz... or Category 5 cable Category 5 cable Category 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors... . An active hub Ethernet hub An Ethernet hub, active hub, network hub, repeater hub or hub is a device for connecting multiple Ethernet devices together and making them act as a single network segment. A hub works at the physical layer of the OSI model. The device is a form of multiport repeater... or switch sits in the middle and has a port for each node. This is also the configuration used for 100BASE-T and gigabit Ethernet. Manchester code Manchester code In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time... d signaling, copper twisted pair cabling, star topology - direct evolution of 1BASE-5. |
| 802.3 (9.9) | Fiber-optic inter-repeater link; the original standard for Ethernet over fiber | |
| 10BASE‑F | 802.3 (15) | A generic term for the family of 10 Mbit/s Ethernet standards using fiber optic cable: 10BASE-FL, 10BASE-FB and 10BASE-FP. Of these only 10BASE-FL is in widespread use. 10 Mbit/s, Manchester code Manchester code In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time... d signaling, fiber pair |
| 10BASE‑FL 10BASE-FL 10BASE-FL is the most commonly used 10BASE-F specification of Ethernet over optical fiber. It replaces the original fiber-optic inter-repeater link specification, but retains compatibility with FOIRL-based equipment... |
802.3 (15&18) | An updated version of the FOIRL standard |
| 10BASE‑FB 10BASE-FB The 10BASE-FB is a network segment used to bridge network hubs. Due to the synchronous operation of 10BASE-FB, delays normally associated with Ethernet repeaters are reduced, thus allowing segment distances to be extended without compromising the collision detection mechanism. The maximum... |
802.3 (15&17) | Intended for backbones connecting a number of hubs or switches; it is now obsolete |
| 10BASE‑FP | 802.3 (15&16) | A passive star network that required no repeater, it was never implemented |
Early Ethernet standards used Manchester coding so that the signal was self-clocking not adversely affected by high-pass filters.
Fast Ethernet
| Name | Standard | Description |
|---|---|---|
| 100BASE‑T | 802.3 (21) | A term for any of the three standard for 100 Mbit/s Ethernet over twisted pair cable. Includes 100BASE-TX, 100BASE-T4 and 100BASE-T2. , 100BASE-TX has totally dominated the market, and is often considered to be synonymous with 100BASE-T in informal usage. All of them use a star topology. |
| 100BASE-TX | 802.3 (24) | 4B5B 4B5B In telecommunication, 4B5B is a form of data communications Block Coding. 4B5B maps groups of four bits onto groups of 5 bits, with a minimum density of 1 bits in the output. When NRZI-encoded, the 1 bits provide necessary clock transitions for the receiver. For example, a run of 4 bits such as... MLT-3 coded signaling, CAT5 Category 5 cable Category 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors... copper cabling with two twisted pairs. |
| 100BASE‑T4 | 802.3 (23) | 8B6T PAM Pulse-amplitude modulation Pulse-amplitude modulation, acronym PAM, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses.... -3 coded signaling, CAT3 Category 3 cable Category 3 cable, commonly known as Cat 3 or station wire, is an unshielded twisted pair cable designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz... copper cabling (as used for 10BASE-T installations) with four twisted pairs (uses all four pairs in the cable). Now obsolete, as CAT5 cabling is the norm. Limited to half-duplex. |
| 100BASE‑T2 | 802.3 (32) | No products exist. PAM-5 coded signaling, CAT3 copper cabling with two twisted pairs, star topology. Supports full-duplex. It is functionally equivalent to 100BASE-TX, but supports old telephone cable. However, special sophisticated digital signal processors are required to handle encoding schemes required, making this option fairly expensive at the time. It arrived well after 100BASE-TX was established in the market. The technology developed for 100BASE-T2 was the foundation for 1000BASE-T. |
| 100BASE‑FX | 802.3 (24) | 4B5B NRZI coded signaling, two strands of multi-mode optical fiber Multi-mode optical fiber Multi-mode optical fiber is a type of optical fiber mostly used for communication over short distances, such as within a building or on a campus... . Maximum length is 400 meters for half-duplex connections (to ensure collisions are detected) or 2 kilometers for full-duplex. |
| 100BASE‑SX | TIA | 100 Mbit/s Ethernet over multi-mode fiber. Maximum length is 300 meters. 100BASE-SX used short wave length (850 nm) optics that was sharable with 10BASE-FL, thus making it possible to have an auto-negotiation scheme and have 10/100 fiber adapters. |
| 100BASE‑BX10 | Proprietary | 100 Mbit/s Ethernet bidirectionally over a single strand of single-mode optical fiber Single-mode optical fiber In fiber-optic communication, a single-mode optical fiber is an optical fiber designed to carry only a single ray of light . Modes are the possible solutions of the Helmholtz equation for waves, which is obtained by combining Maxwell's equations and the boundary conditions... . A multiplexer is used to split transmit and receive signals into different wavelengths allowing them to share the same fiber. Supports up to 10 km. |
| 100BASE-LX10 | Proprietary | 100 Mbit/s Ethernet up to 10 km over a pair of Single Mode Fibers. |
| 100Base‑VG 100BaseVG 100BaseVG is a 100 Mbit/s Ethernet standard specified to run over four pairs of category 3 UTP wires . It is also called 100VG-AnyLAN because it was defined to carry both Ethernet and token ring frame types.... |
802.12 | Standardized by a different IEEE 802 subgroup, 802.12, because it used a different, more centralized form of media access ("Demand Priority"). Championed by only HP, 100VG-AnyLAN (as was the marketing name) was the earliest in the market. It needed four pairs in a Cat-3 cable. Now obsolete (802.12 has been "inactive" since 1997) the standard has been withdrawn. |
One Gbit/s
All of these use a star topology.| Name | Standard | Description |
|---|---|---|
| 1000BASE‑T | 802.3 (40) | PAM-5 Pulse-amplitude modulation Pulse-amplitude modulation, acronym PAM, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses.... coded signaling, At least Category 5 cable Category 5 cable Category 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors... , with Category 5e strongly recommended copper cabling with four twisted pairs. Each pair is used in both directions simultaneously. |
| 1000BASE‑TX | TIA 854 | Only over Cat-6 Category 6 cable Category 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk... copper cabling. Unimplemented. |
| 1000BASE‑SX | 802.3 | 8B10B NRZ Non-return-to-zero In telecommunication, a non-return-to-zero line code is a binary code in which 1's are represented by one significant condition and 0's are represented by some other significant condition , with no other neutral or rest condition. The pulses have more energy than a RZ code... coded signaling, short-range multi-mode fiber (up to 550 m). |
| 1000BASE‑LX | 802.3 | 8B10B NRZ coded signaling, multi-mode fiber (up to 550 m) or single-mode fiber (up to 2 km; can be optimized for longer distances, up to 10 km). |
| 1000BASE‑LH | multi-vendor | over single-mode fiber (up to 100 km). A long-haul solution. |
| 1000BASE‑CX | 802.3 | 8B10B NRZ coded signaling, balanced shielded twisted pair (up to 25 m) over special copper cable. Predates 1000BASE-T and rarely used. |
| 1000BASE‑BX10 | 802.3 | up to 10 km. Bidirectional over single strand of single-mode fibre. |
| 1000BASE‑LX10 | 802.3 | Up to 10 km over a pair of single-mode fibres. |
| 1000BASE‑PX10‑D | 802.3 | downstream (from head-end to tail-ends) over single-mode fiber using point-to-multipoint topology (supports at least 10 km). |
| 1000BASE‑PX10‑U | 802.3 | upstream (from a tail-end to the head-end) over single-mode fiber using point-to-multipoint topology (supports at least 10 km). |
| 1000BASE‑PX20‑D | 802.3 | downstream (from head-end to tail-ends) over single-mode fiber using point-to-multipoint topology (supports at least 20 km). |
| 1000BASE‑PX20‑U | 802.3 | upstream (from a tail-end to the head-end) over single-mode fiber using point-to-multipoint topology (supports at least 20 km). |
| 1000BASE‑ZX | Unknown | Up to 100 km over single-mode fibre. |
| 1000BASE‑KX | 802.3ap | 1 m over backplane |
10 Gbit/s
10 Gigabit Ethernet defines a version of Ethernet with a nominal data rate of 10 Gbit/s, ten times as fast as Gigabit Ethernet. In 2002, the first 10 Gigabit Ethernet standard was published as IEEE Std 802.3ae-2002. Subsequent standards encompassed media types for single-mode fibre (long haul), multi-mode fibre (up to 300 m), copper backplane (up to 1 m) and copper twisted pair (up to 100 m). All 10 gigabit varieties were consolidated into IEEE Std 802.3-2008. , 10 gigabit Ethernet is predominantly deployed in carrier networks, where 10GBASE-LR and 10GBASE-ER enjoy significant market shares.| Name | Standard | Description |
|---|---|---|
| 10GBASE‑SR | 802.3ae | designed to support short distances over deployed multi-mode fiber cabling, it has a range of between 26 m and 82 m depending on cable type. It also supports 300 m operation over a new 2000 MHz·km Modal bandwidth Modal Bandwidth, in the discipline of telecommunications, refers to the signalling rate per distance unit. The signalling rate can typically be measured in MHz, and the modal bandwidth is expressed as MHz·km .... multi-mode fiber. |
| 10GBASE‑LX4 | 802.3ae | uses wavelength division multiplexing to support ranges of between 240 m and 300 m over deployed multi-mode cabling. Also supports 10 km over single-mode fiber. |
| 10GBASE‑LR | 802.3ae | supports 10 km over single-mode fiber |
| 10GBASE‑ER | 802.3ae | supports 40 km over single-mode fiber |
| 10GBASE‑SW | 802.3ae | A variation of 10GBASE-SR using the WAN PHY, designed to interoperate with OC-192 / STM-64 SONET Sonet Sonet may refer to:* Sonet Records, European record label* Synchronous optical networking * Saab Sonett... /SDH equipment |
| 10GBASE‑LW | 802.3ae | A variation of 10GBASE-LR using the WAN PHY, designed to interoperate with OC-192 / STM-64 SONET Sonet Sonet may refer to:* Sonet Records, European record label* Synchronous optical networking * Saab Sonett... /SDH equipment |
| 10GBASE‑EW | 802.3ae | A variation of 10GBASE-ER using the WAN PHY, designed to interoperate with OC-192 / STM-64 SONET Sonet Sonet may refer to:* Sonet Records, European record label* Synchronous optical networking * Saab Sonett... /SDH equipment |
| 10GBASE‑CX4 | 802.3ak | Designed to support short distances over copper cabling, it uses InfiniBand InfiniBand InfiniBand is a switched fabric communications link used in high-performance computing and enterprise data centers. Its features include high throughput, low latency, quality of service and failover, and it is designed to be scalable... 4x connectors and CX4 cabling and allows a cable length of up to 15 m. Was specified by the IEEE Std 802.3an-2006 which has been incorporated into the IEEE Std 802.3-2008. |
| 10GBASE‑T | 802.3an | Uses unshielded twisted-pair wiring. |
| 10GBASE‑LRM | 802.3aq | Extend to 220 m over deployed 500 MHz·km Modal bandwidth Modal Bandwidth, in the discipline of telecommunications, refers to the signalling rate per distance unit. The signalling rate can typically be measured in MHz, and the modal bandwidth is expressed as MHz·km .... multimode fiber |
| 10GBASE‑KX4 | 802.3ap | 1 m over 4 lanes of backplane |
| 10GBASE‑KR | 802.3ap | 1 m over a single lane of backplane |
40 and 100 Gbit/s
This version of Ethernet specified two speeds and was standardized in June 2010 as IEEE 802.3ba, with one addition in March 2011 as IEEE 802.3bg.The nomenclature is as follows:
| 40 gigabits/second | 100 gigabits/second | Standard | Description |
|---|---|---|---|
| 40GBASE-KR4 | 802.3ba | at least 1 m over a backplane Backplane A backplane is a group of connectors connected in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a complete... |
|
| 40GBASE-CR4 | 100GBASE-CR10 | approximately 7 m over copper cable assembly | |
| 40GBASE-SR4 | 100GBASE-SR10 | at least 100 m over multi-mode fiber | |
| at least 125 m over new 2000 MHz·km Modal bandwidth Modal Bandwidth, in the discipline of telecommunications, refers to the signalling rate per distance unit. The signalling rate can typically be measured in MHz, and the modal bandwidth is expressed as MHz·km .... multi-mode fiber |
|||
| 40GBASE-LR4 | 100GBASE-LR4 | at least 10 km over single-mode fiber | |
| 100GBASE-ER4 | at least 40 km over single-mode fiber | ||
| 40GBASE-FR | 802.3bg | Single-mode fiber over 2 km | |
"First mile"
For providing Internet accessInternet access
Many technologies and service plans for Internet access allow customers to connect to the Internet.Consumer use first became popular through dial-up connections in the 20th century....
service directly from providers to homes and small businesses:
| Name | Standard | Description |
|---|---|---|
| 10BaseS | Proprietary | Ethernet over VDSL Very high data rate Digital Subscriber Line Very-high-bit-rate digital subscriber line is a digital subscriber line technology providing faster data transmission over a single flat untwisted or twisted pair of copper wires , and on coaxial cable ; using the frequency band from 25 kHz to... , used in Long Reach Ethernet Long Reach Ethernet Long Reach Ethernet was a proprietary networking protocol marketed by Cisco Systems, intended to support multi-megabit performance over telephone-grade unshielded twisted pair wiring over distances up to 5,000 feet .... products |
| 2BASE-TL | IEEE 802.3ah-2004 | Over telephone wires |
| 10PASS-TS | ||
| 100BASE-LX10 100BASE-BX10 1000BASE-LX10 1000BASE-BX10 |
Single-mode fiber-optics | |
| 1000BASE-PX10 1000BASE-PX20 |
Passive optical network Passive optical network A passive optical network is a point-to-multipoint, fiber to the premises network architecture in which unpowered optical splitters are used to enable a single optical fiber to serve multiple premises, typically 16-128. A PON consists of an optical line terminal at the service provider's central... |
Twisted-pair cable
Several varieties of Ethernet were specifically designed to run over 4-pair copper structured cablingStructured cabling
Structured cabling is building or campus telecommunications cabling infrastructure that consists of a number of standardized smaller elements called subsystems.Structured cabling falls into six subsystems:...
already installed in many locations.
ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
recommends using Category 6 cable
Category 6 cable
Category 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk...
for new installations.
| Pin | Pair | Color | telephone | 10BASE-T | 100BASE-TX | 1000BASE-T | PoE mode A | PoE mode B |
|---|---|---|---|---|---|---|---|---|
| 1 | 3 |  |
- | TX+ | z | bidi | 48V out | - |
| 2 | 3 |  |
- | TX- | z | bidi | 48V out | - |
| 3 | 2 |  |
- | RX+ | z | bidi | 48V return | - |
| 4 | 1 |  |
ring | - | - | bidi | - | 48V out |
| 5 | 1 |  |
tip | - | - | bidi | - | 48V out |
| 6 | 2 |  |
- | RX- | z | bidi | 48V return | - |
| 7 | 4 |  |
- | - | - | bidi | - | 48V return |
| 8 | 4 |  |
- | - | - | bidi | - | 48V return |
Combining 10Base-T (or 100BASE-TX) with "IEEE 802.3af mode A" allows a hub to transmit both power and data over only two pairs. This was designed to leave the other two pairs free for analog telephone signals. The pins used in "IEEE 802.3af Mode B" supplies power over the "spare" pairs not used by 10BASE-T and 100BASE-TX.
In a departure from both 10BASE-T and 100BASE-TX, 1000BASE-T uses all four cable pairs for simultaneous transmission in both directions through the use of echo cancellation
Echo cancellation
'The term echo cancellation is used in telephony to describe the process of removing echo from a voice communication in order to improve voice quality on a telephone call...
.
Minimum cable lengths
All copper Ethernet segments that run the collision detection (CD) portion of CSMA/CD have a minimum cable length to function properly because of reflectionsSignal reflection
Signal reflection occurs when a signal is transmitted along a transmission medium, such as a copper cable or an optical fiber, some of the signal power may be reflected back to its origin rather than being carried all the way along the cable to the far end. This happens because imperfections in the...
. This applies only to 10BASE-T and 100BASE-TX standards; The 1000BASE-TX standard is covered at the end of this section.
Fiber connections have minimum cable lengths due to level requirements on received signals. Fiber ports designed for long-haul wavelengths require a signal attenuator
Attenuator (electronics)
An attenuator is an electronic device that reduces the amplitude or power of a signal without appreciably distorting its waveform.An attenuator is effectively the opposite of an amplifier, though the two work by different methods...
if used within a building.
Industrial Ethernet applications use a star topology with no collisions so that no minimum cable length is required.
1000BASE-TX supports half-duplex mode, making collisions possible. Consequently, the 1000BASE-TX standard requires a minimum cable length for collision detection to function properly; to avoid this in Gigabit Ethernet, small frames are padded into the transmission in half-duplex mode.
Related standards
Some networking standards are not part of the IEEE 802.3 Ethernet standard, but support the Ethernet frame format, and are capable of interoperating with it.- LattisNetLattisNetLattisNet was a family of computer networking hardware and software products built and sold by SynOptics Communications during the 1980s...
—A SynOpticsSynOpticsSynOptics Communications was a Santa Clara, California-based early computer network equipment vendor from 1985 until 1994, when it began a series of mergers....
pre-standard twisted-pair 10 Mbit/s variant. - 100BaseVG100BaseVG100BaseVG is a 100 Mbit/s Ethernet standard specified to run over four pairs of category 3 UTP wires . It is also called 100VG-AnyLAN because it was defined to carry both Ethernet and token ring frame types....
—An early contender for 100 Mbit/s Ethernet. It runs over Category 3 cabling. Uses four pairs. Commercial failure. - TIA 100BASE-SX—Promoted by the Telecommunications Industry AssociationTelecommunications Industry AssociationThe Telecommunications Industry Association is accredited by the American National Standards Institute to develop voluntary, consensus-based industry standards for a wide variety of ICT products, and currently represents nearly 400 companies...
. 100BASE-SX is an alternative implementation of 100 Mbit/s Ethernet over fiber; it is incompatible with the official 100BASE-FX standard. Its main feature is interoperability with 10BASE-FL, supporting autonegotiation between 10 Mbit/s and 100 Mbit/s operation – a feature lacking in the official standards due to the use of differing LED wavelengths. It is targeted at the installed base of 10 Mbit/s fiber network installations. - TIA 1000BASE-TX—Promoted by the Telecommunications Industry AssociationTelecommunications Industry AssociationThe Telecommunications Industry Association is accredited by the American National Standards Institute to develop voluntary, consensus-based industry standards for a wide variety of ICT products, and currently represents nearly 400 companies...
, it was a commercial failure, and no products exist. 1000BASE-TX uses a simpler protocol than the official 1000BASE-T standard so the electronics can be cheaper, but requires Category 6Category 6 cableCategory 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk...
cabling. - G.hnG.hnG.hn is the common name for a home network technology family of standards developed under the International Telecommunication Union's Standardization arm and promoted by the HomeGrid Forum...
—A standard developed by ITU-TITU-TThe ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
and promoted by HomeGrid Forum for high-speed (up to 1 Gbit/s) local area networkLocal area networkA local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
s over existing home wiring (coaxial cablesEthernet over coaxEthernet over Coax is a family of technologies that supports the transmission of Ethernet frames over coaxial cable.- History :The first Ethernet standard, known as 10BASE5 in the family of IEEE 802.3, specified baseband operation over coaxial cable...
, power linesPower line communicationPower line communication or power line carrier , also known as power line digital subscriber line , mains communication, power line telecom , power line networking , or broadband over power lines are systems for carrying data on a conductor also used for electric power transmission.A wide range...
and phone lines). G.hnG.hnG.hn is the common name for a home network technology family of standards developed under the International Telecommunication Union's Standardization arm and promoted by the HomeGrid Forum...
defines an Application Protocol Convergence (APC) layer that accepts Ethernet frames and encapsulates them into G.hn MSDUs.
Other networking standards do not use the Ethernet frame format but can still be connected to Ethernet using MAC-based bridging.
- 802.11—Standards for wireless local area networkLocal area networkA local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
s (LANs), sold with brand name Wi-FiWi-FiWi-Fi or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, or digital audio player, can connect to the Internet via a wireless network access point. An access point has a range of about 20... - 802.16—Standards for wireless metropolitan area networkMetropolitan area networkA metropolitan area network is a computer network that usually spans a city or a large campus. A MAN usually interconnects a number of local area networks using a high-capacity backbone technology, such as fiber-optical links, and provides up-link services to wide area networks and the...
s (MANs), sold with brand name WiMAXWiMAXWiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...
Other special-purpose physical layers include Avionics Full-Duplex Switched Ethernet
Avionics Full-Duplex Switched Ethernet
Avionics Full-Duplex Switched Ethernet is a data network for safety-critical applications that utilizes dedicated bandwidth while providing deterministic Quality of Service . AFDX is based on IEEE 802.3 Ethernet technology and utilizes commercial off-the-shelf components...
and TTEthernet
TTEthernet
TTEthernet is a computer network technology marketed by TTTech Computertechnik AG for use in airplanes and other real-time applications.-Description:...
— Time-Triggered Ethernet for embedded systems.