Ethernet in the First Mile


Ethernet in the First Mile

Ethernet in the First Mile (EFM), also known as IEEE 802.3ah, is a collection of protocols specified in IEEE 802.3, defining the Ethernet in the access networks, i.e. first or last mile.

With Wide, Metro and Local Area Networks already standardized, the EFM allows continuous standard Ethernet network across the globe, eliminating non-native transport such as Ethernet over ATM from the access networks.

EFM defines how Ethernet can be transmitted over new media types:
* Voice-grade copper. These new EFM copper (EFMCu) interfaces allow optional multi-pair aggregation
* Long wavelength single fiber (as well as long wavelength dual-strand fiber)
* Point-To-Multipoint (P2MP) fiber. These new interfaces are known under collective name Ethernet over passive optical networks (EPON).

EFM also addresses other issues, required for mass deployment of Ethernet services, such as operations, administration & management (OA&M) and compatibility with existing technologies (e.g. spectral compatibility for copper).

History

The IEEE 802.3ah working group was established in 2001 in order to enable Ethernet penetration into the Access Networks. In parallel the EFM Alliance (EFMA) was formed by the participating vendors, to promote Ethernet subscriber access technology and support the IEEE standard effort. [ [http://www.lightreading.com/document.asp?doc_id=10223 Extreme Launches Ethernet Alliance] , "Light Reading", December 11, 2001]

The EFM standard was approved on 24 Jun 2004 and published on 07 Sep 2004 as IEEE 802.3ah-2004. In 2005 it was included into the base IEEE 802.3 standard. The EFMA got absorbed by the Metro Ethernet Forum. [ [http://www.lightreading.com/document.asp?doc_id=69721&site=ofc MEF Absorbs EFMA] , "Light Reading", March 8, 2005]

Recently, starting in early 2006, work began on a very high-speed 10 Gigabit/second EPON (XEPON or 10-GEPON) standard (http://www.ieee802.org/3/av/).

Details

The EFM defines the following new Ethernet physical layer (PHY) interfaces:
# EFMC - EFM Copper
#* 2BASE-TL -- 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 kft), using ITU-T G.991.2 (G.SHDSL.bis) technology over a single copper pair.
#* 10PASS-TS -- 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-T G.993.1 (VDSL) technology over a single copper pair.
#EFMF - EFM Fiber
#* 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.
#EFM PON - EFM Passive Optical Network
#* 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 OAM, including discovery, link monitoring, remote fault indication, loopbacks and variable access.

See also

* IEEE 802.3

Further reading

*
*

References

External links

* [http://standards.ieee.org/getieee802/802.3.html Download IEEE 802.3] - EFM is contained in section 5
* [http://www.ieee802.org/3/efm IEEE 802.3ah] - Ethernet in the First Mile working group archives
* [http://www.ethernetinthefirstmile.com/ Ethernet in the First Mile FAQ]
*
* [http://www.iol.unh.edu/training/efm/ EFM Knowledge Base] at the UNH-IOL


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Ethernet in the First Mile — (EFM) ist ein Protokoll, welches im Ethernet Standard IEEE 802.3ah definiert ist. Das EFM Protokoll hat folgende Funktionen: ständige Überwachung von Access Leitungen (erste/letzte Meile) auf Ethernet Überwachung von Equipment, welches beim… …   Deutsch Wikipedia

  • Ethernet in the First Mile Alliance — Infobox Non profit Non profit name = Ethernet in the First Mile Alliance Non profit Non profit type = Industry Consortium founded date = 2001 founder = location = origins = key people = area served = focus = Ethernet in the Access Networks method …   Wikipedia

  • Ethernet — im TCP/IP‑Protokollstapel: Anwendung HTTP IMAP SMTP DNS … Transport TCP UDP Internet …   Deutsch Wikipedia

  • Ethernet powerlink — является детерминированным в режиме реального времени протоколом для стандартного Ethernet. Это открытый управляемый протокол Ethernet POWERLINK Standardization Group (EPSG). Он был введен австрийской автоматизационной компанией B R в 2001 году.… …   Википедия

  • Ethernet extender — An Ethernet extender (also network extender or LAN extender) is any device used to extend an Ethernet or network segment beyond its inherent distance limitation which is approximately 100 metres (330 ft) for most common forms of twisted pair …   Wikipedia

  • Ethernet — Кабель UTP с разъемом 8P8C (ошибочно называемый RJ 45), используемый в Ethernet сетях стандартов 10BASE T, 100BASE T(x) и 1 …   Википедия

  • Ethernet sur le premier kilomètre — IEEE 802.3ah IEEE 802.3ah, appelée également Ethernet in the First Mile, est une norme ratifiée en juin 2004 et appartenant au standard IEEE 802.3 (Ethernet). Celle ci comprend un ensemble de protocoles définissant trois types de liaison :… …   Wikipédia en Français

  • Ethernet — An 8P8C modular connector (often called RJ45) commonly used on cat 5 cables in Ethernet networks Ethernet   …   Wikipedia

  • Ethernet frame — A data packet on an Ethernet link is called an Ethernet frame. A frame begins with Preamble and Start Frame Delimiter. Following which, each Ethernet frame continues with an Ethernet header featuring destination and source MAC addresses. The… …   Wikipedia

  • Ethernet over twisted pair — cable (upper) and 8P8C plug (lower) 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… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.