Ethernet in the First Mile
Encyclopedia
Ethernet in the first mile (EFM) refers to using one of the Ethernet
family of computer network
protocols between a telecommunications company and a customer's premise. From the customer's point of view it is their "first" mile, although from the access network
s' point of view it is known as the "last mile
". A working group of the Institute of Electrical and Electronics Engineers
(IEEE) produced the standards known as IEEE 802.3ah-2004, which were later included in the overall standard IEEE 802.3-2008
.
Although it often is used for businesses, it can also be known as Ethernet to the Home (ETTH).
One family of standards known as EPON uses a passive optical network
.
, metro
and local
area networks using various forms of Ethernet, the goal was to eliminate non-native transport such as Ethernet over Asynchronous Transfer Mode
(ATM) from access networks.
One early effort was the EtherLoop technology invented at Nortel
Networks in 1996, and then spun off into the company Elastic Networks in 1998.
Its principal inventor was Jack Terry. The hope was to combine the packet-based nature of Ethernet with the ability of Digital Subscriber Line
(DSL) technology to work over existing telephone access wires.
The name comes from local loop
, which traditionally describes the wires from a telephone company office to a subscriber.
The protocol was half-duplex with control from the provider side of the loop. It adapted to line conditions with a peak of 10 Mbit/s advertised, but 4-6 Mbit/s more typical, at a distance of about 12000 feet (3,657.6 m). Symbol rate
s were 1 Mbaud
or 1.67 Mbaud, with 2, 4, or 6 bits per symbol.
The EtherLoop product name was registered as a trademark in the US and Canada.
The EtherLoop technology was eventually purchased by Paradyne Networks in 2002,
which was in turn purchased by Zhone Technologies
in 2005.
Another effort was the concept promoted by Michael Silverton
of using Ethernet variants that used fiber optic communication to residential as well as business customers. This was an example of what has become known as fiber to the home (FTTH). The Fiberhood Networks company provided this service from 1999 to 2001.
Some early products around 2000 were marketed as 10BaseS by Infineon Technologies
, although they did not technically use baseband
signalling, but rather passband
as in Very high data rate Digital Subscriber Line
(VDSL) technology.
A patent was filed in 1997 by Peleg Shimon, Porat Boaz, Noam Alroy, Rubinstain Avinoam and Sfadya Yackow.
Long Reach Ethernet
was the product name used by Cisco Systems
starting in 2001. It supported modes of 5 Mbit/s, 10 Mbit/s and 15 Mbit/s depending on distance.
In October 2000 Howard Frazier issued a call for interest on "Ethernet in the Last Mile".
At the November 2000 meeting, IEEE 802.3 created the "Ethernet in the First Mile" study group, and on July 16, 2001 the 802.3ah working group.
In parallel participating vendors formed the Ethernet in the First Mile Alliance (EFMA) in December 2001 to promote Ethernet subscriber access technology and support the IEEE standard efforts.
At an early meeting, the EtherLoop technology was called 100BASE-CU and another technology called EoVDSL for Ethernet over VDSL.
The working group's EFM standard was approved on June 24, 2004 and published on September 7, 2004 as IEEE 802.3ah-2004. In 2005 it was included into the base IEEE 802.3 standard. In 2005, the EFMA was absorbed by the Metro Ethernet Forum
.
In early 2006, work began on an even higher-speed 10 Gigabit/second Ethernet Passive optical network
(XEPON or 10G-EPON) standard, ratified in 2009 as IEEE 802.3av
.
(PHY
) interfaces:
EFM also addresses other issues, required for mass deployment of Ethernet services, such as operations, administration and management (OA&M
) and compatibility with existing technologies (such as plain old telephone service
spectral compatibility for copper twisted pair
).
is a common example of fiber to the home.
Additionally clause 57 defines link-level OA&M, including discovery, link monitoring, remote fault indication, loopbacks and variable access.
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....
protocols between a telecommunications company and a customer's premise. From the customer's point of view it is their "first" mile, although from the access network
Access network
An access network is that part of a telecommunications network which connects subscribers to their immediate service provider. It is contrasted with the core network, which connects local providers to each other...
s' point of view it is known as the "last mile
Last mile
The "last mile" or "last kilometer" is the final leg of delivering connectivity from a communications provider to a customer. The phrase is therefore often used by the telecommunications and cable television industries. The actual distance of this leg may be considerably more than a mile,...
". A working group of the Institute of Electrical and Electronics Engineers
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
(IEEE) produced the standards known as IEEE 802.3ah-2004, which were later included in the overall standard 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...
.
Although it often is used for businesses, it can also be known as Ethernet to the Home (ETTH).
One family of standards known as EPON uses a 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...
.
History
With wideWide area network
A wide area network is a telecommunication network that covers a broad area . Business and government entities utilize WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations...
, metro
Metropolitan area network
A 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...
and local
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
area networks using various forms of Ethernet, the goal was to eliminate non-native transport such as Ethernet over Asynchronous Transfer Mode
Asynchronous Transfer Mode
Asynchronous Transfer Mode is a standard switching technique designed to unify telecommunication and computer networks. It uses asynchronous time-division multiplexing, and it encodes data into small, fixed-sized cells. This differs from approaches such as the Internet Protocol or Ethernet that...
(ATM) from access networks.
One early effort was the EtherLoop technology invented at Nortel
Nortel
Nortel Networks Corporation, formerly known as Northern Telecom Limited and sometimes known simply as Nortel, was a multinational telecommunications equipment manufacturer headquartered in Mississauga, Ontario, Canada...
Networks in 1996, and then spun off into the company Elastic Networks in 1998.
Its principal inventor was Jack Terry. The hope was to combine the packet-based nature of Ethernet with the ability of Digital Subscriber Line
Digital Subscriber Line
Digital subscriber line is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop. In telecommunications marketing, the term DSL is widely understood to mean Asymmetric Digital Subscriber Line ,...
(DSL) technology to work over existing telephone access wires.
The name comes from local loop
Local loop
In telephony, the local loop is the physical link or circuit that connects from the demarcation point of the customer premises to the edge of the carrier or telecommunications service provider's network...
, which traditionally describes the wires from a telephone company office to a subscriber.
The protocol was half-duplex with control from the provider side of the loop. It adapted to line conditions with a peak of 10 Mbit/s advertised, but 4-6 Mbit/s more typical, at a distance of about 12000 feet (3,657.6 m). Symbol rate
Symbol rate
In digital communications, symbol rate is the number of symbol changes made to the transmission medium per second using a digitally modulated signal or a line code. The Symbol rate is measured in baud or symbols/second. In the case of a line code, the symbol rate is the pulse rate in pulses/second...
s were 1 Mbaud
Baud
In telecommunications and electronics, baud is synonymous to symbols per second or pulses per second. It is the unit of symbol rate, also known as baud rate or modulation rate; the number of distinct symbol changes made to the transmission medium per second in a digitally modulated signal or a...
or 1.67 Mbaud, with 2, 4, or 6 bits per symbol.
The EtherLoop product name was registered as a trademark in the US and Canada.
The EtherLoop technology was eventually purchased by Paradyne Networks in 2002,
which was in turn purchased by Zhone Technologies
Zhone Technologies
Zhone Technologies, Inc. is a provider of telecommunications networking equipment founded in 1999.It is headquartered in Oakland, California. Zhone is ISO 9001:2008 certified in the manufacture and service of telecommunications equipment.-Corporate history :...
in 2005.
Another effort was the concept promoted by Michael Silverton
Michael Silverton
-Biography:Silverton built the first all-optical Ethernet in the first mile networks in Palo Alto, California in 1999 to 2000, as the result of research and work that first began in 1991 in Phoenix, Arizona....
of using Ethernet variants that used fiber optic communication to residential as well as business customers. This was an example of what has become known as fiber to the home (FTTH). The Fiberhood Networks company provided this service from 1999 to 2001.
Some early products around 2000 were marketed as 10BaseS by Infineon Technologies
Infineon Technologies
Infineon Technologies AG is a German semiconductor manufacturer and was founded on April 1, 1999, when the semiconductor operations of the parent company Siemens AG were spun off to form a separate legal entity. , Infineon has 25,149 employees worldwide...
, although they did not technically use baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...
signalling, but rather passband
Passband
A passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated.A bandpass filtered signal , is known as a bandpass signal, as opposed to a baseband signal....
as in Very high data rate Digital Subscriber Line
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...
(VDSL) technology.
A patent was filed in 1997 by Peleg Shimon, Porat Boaz, Noam Alroy, Rubinstain Avinoam and Sfadya Yackow.
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 ....
was the product name used by Cisco Systems
Cisco Systems
Cisco Systems, Inc. is an American multinational corporation headquartered in San Jose, California, United States, that designs and sells consumer electronics, networking, voice, and communications technology and services. Cisco has more than 70,000 employees and annual revenue of US$...
starting in 2001. It supported modes of 5 Mbit/s, 10 Mbit/s and 15 Mbit/s depending on distance.
In October 2000 Howard Frazier issued a call for interest on "Ethernet in the Last Mile".
At the November 2000 meeting, IEEE 802.3 created the "Ethernet in the First Mile" study group, and on July 16, 2001 the 802.3ah working group.
In parallel participating vendors formed the Ethernet in the First Mile Alliance (EFMA) in December 2001 to promote Ethernet subscriber access technology and support the IEEE standard efforts.
At an early meeting, the EtherLoop technology was called 100BASE-CU and another technology called EoVDSL for Ethernet over VDSL.
The working group's EFM standard was approved on June 24, 2004 and published on September 7, 2004 as IEEE 802.3ah-2004. In 2005 it was included into the base IEEE 802.3 standard. In 2005, the EFMA was absorbed by the Metro Ethernet Forum
Metro Ethernet Forum
The Metro Ethernet Forum , founded in 2001, is a nonprofit international industry consortium, dedicated to worldwide adoption of Carrier Ethernet networks and services....
.
In early 2006, work began on an even higher-speed 10 Gigabit/second Ethernet 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...
(XEPON or 10G-EPON) standard, ratified in 2009 as IEEE 802.3av
10G-EPON
The 10 Gbit/s Ethernet Passive Optical Network standard, better known as 10G-EPON allows computer network connections over telecommunication provider infrastructure...
.
Description
EFM defines how Ethernet can be transmitted over new media types using new Ethernet physical layerEthernet physical layer
The Ethernet physical layer is the physical layer component of the Ethernet family of computer network standards.The Ethernet physical layer evolved over a considerable time span and encompasses quite a few physical media interfaces and several magnitudes of speed...
(PHY
PHY
PHY is an abbreviation for the physical layer of the OSI model.An instantiation of PHY connects a link layer device to a physical medium such as an optical fiber or copper cable. A PHY device typically includes a Physical Coding Sublayer and a Physical Medium Dependent layer. The PCS encodes and...
) interfaces:
- Voice-grade copper. These new EFM copper (EFMCu) interfaces allow optional multi-pair aggregation
- Long wavelength single optical fiberOptical fiberAn 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...
(as well as long wavelength dual-strand fiber) - Point-to-multipoint (P2MP) fiber. These new interfaces are known under the collective name of Ethernet over passive optical networkPassive optical networkA 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...
s (EPON).
EFM also addresses other issues, required for mass deployment of Ethernet services, such as operations, administration and management (OA&M
OA&M
Operations, administration and management or operations, administration and maintenance is a general term used to describe the processes, activities, tools, standards, etc involved with operating, administering, managing and maintaining any system...
) and compatibility with existing technologies (such as plain old telephone service
Plain old telephone service
Plain old telephone service is the voice-grade telephone service that remains the basic form of residential and small business service connection to the telephone network in many parts of the world....
spectral compatibility for copper 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...
).
Copper wires
- 2BASE-TL2BASE-TL2BASE-TL is an IEEE 802.3-2008 Physical Layer specification for a full-duplex long reach point-to-point Ethernet link over voice-grade copper wiring...
-- defined in clauses 61 and 63. Full-duplex long reach Point-to-Point link over voice-grade copper wiring. 2BASE-TL PHY can deliver a minimum of 2 Mbit/s and a maximum of 5.69 Mbit/s over distances of up to 2700 m (9,000 ft), using ITU-TITU-TThe ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
G.991.2 (G.SHDSL.bis) technology over a single copper pair. - 10PASS-TS10PASS-TS10PASS-TS is an IEEE 802.3-2008 Physical Layer specification for a full-duplex short reach point-to-point Ethernet link over voice-grade copper wiring, used in Ethernet in the first mile applications....
-- defined in clauses 61 and 62. Full-duplex short reach Point-to-Point link over voice-grade copper wiring. 10PASS-TS PHY can deliver a minimum of 10 Mbit/s over distances of up to 750 m (2460 ft), using ITU G.993.1ITU G.993.1ITU G.993.1 is an ITU standard for DSL that defines VDSL.-External links:***...
(VDSL) technology over a single copper pair.
Active fiber optics
- 100BASE-LX10 defined in clause 58, providing point-to-point 100 Mbit/s Ethernet links over a pair of single-mode fibers up to at least 10 km.
- 100BASE-BX10 defined in clause 58, providing point-to-point 100 Mbit/s Ethernet links over an individual single-mode fiber up to at least 10 km.
- 1000BASE-LX10 defined in clause 59, providing point-to-point 1000 Mbit/s Ethernet links over a pair of single-mode fibers up to at least 10 km.
- 1000BASE-BX10 defined in clause 59, providing point-to-point 1000 Mbit/s Ethernet links over an individual single-mode fiber up to at least 10 km.
Passive optical network
The use of a passive optical networkPassive 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...
is a common example of fiber to the home.
- 1000BASE-PX10 defined in clause 60, providing P2MP 1000 Mbit/s Ethernet links over PONs up to at least 10 km.
- 1000BASE-PX20 defined in clause 60, providing P2MP 1000 Mbit/s Ethernet links over PONs up to at least 20 km.
Additionally clause 57 defines link-level OA&M, including discovery, link monitoring, remote fault indication, loopbacks and variable access.
External links
- Download IEEE 802.3 - EFM is contained in section 5
- Ethernet in the First Mile FAQ
- EFM Knowledge Base at the UNH-IOL