Miscellaneous

Ethernet IEEE 802.3 Standards

Ethernet IEEE 802.3 Standards

Like any major system used within IT or any other area, it requires standards to be written and maintained. This enables different manufacturers to develop their own products in a way that will operate with products from other manufacturers.

It has been shown that having an open standard like this which also develops and moves forwards to meet the requirements of the industry is likely to gain more success - this has certainly been true of Ethernet.

Over the years, the Ethernet standard has developed to meet the ongoing requirements of the industry. It has grown to reflect the changing approaches of the IT industry, enabling it to provide connectivity for local area networks and metropolitan area networks.

Today, there are many Ethernet standards, and looking at their development over the years, it is possible to see how the standard has moved with the times, increasing speeds and introducing more capabilities.

As a result, today, Ethernet is used for everything from use within large scale networks where Ethernet switches, routers and other items are used to the smaller home and business local area networks where items like Ethernet switches, Ethernet routers, computers, printers and many other items use Ethernet. As Ethernet has been standardised, users can select items from a host of different suppliers and manufacturers.

IEEE Ethernet standards authority

Ethernet standards are written and maintained by the IEEE, the Institute of Electrical and Electronic Engineers which has its corporate office in New York City and its operations centre in Piscataway, New Jersey.

The IEEE develops and maintains a large number of standards associated with the electrical and electronics industries - another very popular one is that for Wi-Fi which is standardised as IEEE 802.11.

In fact the IEEE has over 1100 active standards, and around 600 more under development. One of the more notable are the IEEE 802 LAN/MAN group of standards, of which IEEE 802.3, Ethernet is one of the more widely known along with 802.11 Wi-Fi. There are naturally many others in this group, but Ethernet and Wi-Fi are the most widely used.

The IEEE standards for Ethernet are all based around 802.3, and it supports the IEEE 802.1 standardised network architecture.

IEEE 802.3 standards

The Ethernet standards come under the IEEE 802 section which deal with local area networks and metropolitan area networks. In particular, IEEE 802.3 defines Ethernet.

The IEEE 802.3 standard references all include the IEEE 802.3 nomenclature as standard. Different releases and variants of the standard are then designated by different designated letters after the 802.3 reference, i.e. IEEE 802.3*.

There are many different standards that come under the IEEE 802.3 banner. The different IEEE 802.3 standards define different aspects of Ethernet covering the physical layer and data link layer's media access control (MAC) of wired Ethernet.

Some of the individual standards may introduce new versions or flavours of Ethernet to keep pace with the growing requirements for speed and performance, whereas other standards may define aspects like the data frames used.

It is also possible to see several different standards for different versions of what may be considered to be the same version of Ethernet. Fir example there are several standards for 1Gb Ethernet as one was used fort he original release covering mainly fibre media, another for copper using Cat 5, and another for additional versions of fibre based 1 Gb Ethernet.

The different standards with their numbers are outlined in the table below:


Ethernet IEEE 802.3 Standards Supplements & Releases
Standard
Supplement
YearDescription
802.31983This first IEEE standard for Ethernet defined 10base5, 10 Mbps over thick coax.
802.3a198510Base-2 (thin Ethernet), 10 Mbps over thin coax.
802.3b198510-Broad-36
802.3c198610 Mb/s repeater specifications (clause 9)
802.3d1987FOIRL (fiber link)
802.3e19871-Base-5
802.3i199010Base-T (twisted pair)
802.3j199310Base-F (fiber optic)
802.3u1995100Base-T (Fast Ethernet and auto-negotiation)
802.3x1997Full duplex
802.3z19981000Base-X (Gigabit Ethernet)
802.3ab19991000Base-T (Gigabit Ethernet over twisted pair), 1 Gbps.
802.3ac1998VLAN tag (frame size extension to 1522 bytes) - this expanded the maximum frame size to 1522 bytes.
802.3ad2000Parallel links (link aggregation)
802.3ae200210-Gigabit Ethernet
802.3af2003Power over Ethernet - first standard release for this technology
802.3ah2004Ethernet for the First Mile
802.3ak200410G-Base-CX4 10Gbps, Ethernet over twinaxial cables.
802.3an200610G-Base-T 10Gbps over unshielded twisted pair, UTP.
802.3ap2007Backplane Ethernet, 1 & 10 Gbps over a PCB.
802.3aq20061-G-Base-LRM 10 Gbps over multimode fibre.
802.3as2005Frame expansion
802.3at2005Power over Ethernet Plus - enhancements to 25.5W
802.3au2006Isolation requirements for Power over Ethernet
802.3av200910 Gbps
802.3ax2008Link aggregation - see IEEE 802.1ax
802.3az2010Energy efficient Ethernet
802.3ba201040Gbps & 100Gbps Ethernet
802.3bc2009Update of Ethernet Type, Length & Value, TLVs that were previously specified in 802.1AB to 802.3
802.3bd2011Priority based flow control
802.3bf2011Provision of accurate indication of transmission and reception initiation times of some packets to support IEEE P802.1AS

New technologies are being added to the list of IEEE 802.3 standards to keep pace with technology.

Ethernet version numbering

There is a convention for describing the different forms of Ethernet. For example 10BASE-T and 100BASE-T are widely seen in the technical articles and literature. The designator consists of a three parts:

  • The first number (typically one of 10, 100, or 1000) indicates the transmission speed in megabits per second. Some of the higher speed Ethernet standards exceed 1Gbps and terms like 10G are being used for speeds of 10 Gbps.
  • The second term indicates transmission type: BASE = baseband; BROAD = broadband.
  • The last number indicates segment length. A 5 means a 500-meter (500-m) segment length from original Thicknet. In the more recent versions of the IEEE 802.3 standard, letters replace numbers. For example, in 10BASE-T, the T means unshielded twisted-pair cables. Further numbers indicate the number of twisted pairs available. For example in 100BASE-T4, the T4 indicates four twisted pairs.

Thus 100BASE-T is a copper version of 100 Mbps Ethernet using twisted pair wires. Similarly 10GBASE-T is a 10Gb Ethernet system using twisted pair cables like Cat5, 6, etc.

It worth noting that the speeds are quoted in terms of bits per second. Accordingly the speeds should be divided by a factor of eight to determine the speed in terms of bytes per second, Bps, rather than bits per second, bps.

The copper based versions of Ethernet are widely used for many local area networks and the associated items including computers, Ethernet routers, Ethernet switches and many other items.

Ethernet IEEE802.3 standard has undergone many additions and the process is on-going. This enables the Ethernet standard to keep pace with current developments and remain a forerunner in the data communications and connectivity arenas.

The standards show that over time, the speeds have increased and a variety of new facilities have been introduced. With further updates being worked upon by the IEEE 802.3 working group, the standard is set to move forwards and keep up with the ever increasing requirements placed upon it.

As Ethernet is so popular and capable, it is used in a whole variety of items from professional backbone Ethernet switches for large networks, to items for much smaller local area networks including Ethernet routers, Ethernet switches, computers, printers and the like.

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Watch the video: Ethernet (December 2021).