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Module 7Ethernet Technologies

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www.pnj.ac.idObjectives

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www.pnj.ac.idTypes of Ethernet

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Types of Ethernet• 1980s---The 10-Mbps Ethernet standard remained

virtually unchanged until 1995 when IEEE announced a standard for a 100 Mbps Fast Ethernet

• The standards for Gigabit Ethernet emerged in only three years.

• An even faster Ethernet version, 10 Gigabit Ethernet, is now widely available and still faster versions are being developed

• 10BASE5, 10BASE2, and 10BASE-T Ethernet are now considered Legacy Ethernet

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www.pnj.ac.idParameters for 10 Mbps Ethernet Operation

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www.pnj.ac.idEthernet Frame

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www.pnj.ac.idManchester Encoding

• In this technique, the actual binary data to be transmitted over the cable are not sent as a sequence of logic 1's and 0's

• Manchester encoding follows the rules shown below:

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www.pnj.ac.idManchester Encoding Examples

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www.pnj.ac.id10BASE5 Architecture Example

Thicknet

• Bus topology

• Coaxial cable

Heavy

Hard to work with

• Half-duplex

• 500m

• 5-4-3-2-1 rule

• Manchester Encoding

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www.pnj.ac.id10BASE2 Network Design Limits

Thinnet

• Bus topology

• Coaxial cable

Lighter

Easier to work with

• BNC connectors

• Half-duplex

• 185m

• 5-4-3-2-1 rule

• Manchester

Encoding

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www.pnj.ac.id5-4-3 Repeater Rule

• 10-Mbps Ethernet operates within the timing limits offered by a series of not more than five segments separated by no more than four repeaters. This is known as the 5-4-3 rule.

• No more than four repeaters may be connected in series between any two distant stations. There can also be no more than three populated segments between any two distant stations

• NOTE: This only applies to the old 10Mbps coax and does NOT apply to twisted pair

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www.pnj.ac.id10BASE-T Repeated Network Design Limits

Star Topology

• UTP cable

Lighter

Easier to work with

Cheaper

Solid or stranded

• RJ-45 connectors

• Half-duplex or full-duplex

• 100m(90 + 10)

• Manchester Encoding

• Linked hubs add to distance and delay

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www.pnj.ac.id10BASE-T Modular Jack Pinouts

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www.pnj.ac.idParameters for 100-Mbps Ethernet Operation

•100-Mbps Ethernet is also known as Fast Ethernet. •Operates in full duplex and half duplex mode

The two technologies that have become important are •100BASE-TX, which is a copper UTP medium •100BASE-FX, which is a multimode optical fiber medium

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www.pnj.ac.idEthernet Frame

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www.pnj.ac.idMLT-3 Encoding

If the next data signal is a '1' then the output 'transitions' to the next bit in the pattern e.g. if the last output bit was a '-1', and the input bit is a '1', then the next output bit is a '0'. If the next data signal is a '0' then there is no transition which means that the next output bit is the same as last time, in our case a '0'.

100Base-Tx

Uses MLT-3 rather than Manchester encoding

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100BASE-TX Modular Jack Pinout

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Example of Architecture Configuration and Cable Distances

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www.pnj.ac.idTypes of Ethernet

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www.pnj.ac.id1000-Mbps Ethernet ---Gigabit

• The 1000-Mbps Ethernet or Gigabit Ethernet standards IEEE 802.3z represent transmission using both fiber and copper media.

 

• The 1000BASE-LXand SX standard, IEEE 802.3ab, specifies 1 Gbps full duplex over optical fiber.

• The 1000BASE-X standard, IEEE 802.3ab, specifies 1 Gbps full duplex over twisted pair cable.

• At the physical layer, the bit patterns from the MAC layer are converted into symbols.

• Views the link as Point-to-point.

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www.pnj.ac.idParameters for Gigabit Ethernet Operation

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www.pnj.ac.idEthernet Frame

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www.pnj.ac.idOutbound (Tx) 1000Base-T Signal

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www.pnj.ac.idActual 1000Base-T Signal Transmission

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www.pnj.ac.idBenefits of Gigabit Ethernet on Fiber

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www.pnj.ac.idGigabit Ethernet Layers

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www.pnj.ac.id1000BASE-SX and LX

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www.pnj.ac.idGigabit Ethernet Media Comparison

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www.pnj.ac.idGigabit Ethernet Architecture

Maximum 1000BASE-SX Cable Distances

Maximum 1000BASE-LX Cable Distances

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www.pnj.ac.idThe 10GB Ethernet

• 10-Gbps Ethernet (IEEE 802.3ae) was standardized in June 2002.

• It is a full-duplex protocol that uses only optic fiber as a transmission medium.

• The maximum transmission distances depend on the type of fiber being used.

• When using single-mode fiber as the transmission medium, the maximum transmission distance is 40 kilometers (25 miles).

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www.pnj.ac.idParameters for 10-Gbps Ethernet Operation

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www.pnj.ac.id10GBASE LX-4 Signal Multiplexing

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www.pnj.ac.id10-Gigabit Ethernet Implementations

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www.pnj.ac.idFraming Format

• Frame format is the same, allowing interoperability between all varieties of legacy, fast, gigabit, and 10 Gigabit, with no reframing or protocol conversions.

• Any repeater that changes between one Ethernet implementation and another is a Class I repeater

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www.pnj.ac.idFuture of Ethernet

The future of networking media is three-fold:

• Copper (up to 1000 Mbps, perhaps more)

• Wireless (approaching 100 Mbps, perhaps more)

• Optical fiber (currently at 10,000 Mbps and soon to be more)

Copper and wireless media have certain physical and practical limitations on the highest frequency signals that can be transmitted.

This is not a limiting factor for optical fiber in the foreseeable future. The bandwidth limitations on optical fiber are extremely large and are not yet being threatened.

In fiber systems, it is the:-

electronics technology (such as emitters and detectors)

fiber manufacturing processes that most limit the speed.

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www.pnj.ac.idSummary