cisco ccna module 7
TRANSCRIPT
1© 2004, Cisco Systems, Inc. All rights reserved.
Module 7Ethernet Technologies
222© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idObjectives
333© 2004, Cisco Systems, Inc. All rights reserved.
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
555© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idParameters for 10 Mbps Ethernet Operation
666© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idEthernet Frame
777© 2004, Cisco Systems, Inc. All rights reserved.
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
101010© 2004, Cisco Systems, Inc. All rights reserved.
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
111111© 2004, Cisco Systems, Inc. All rights reserved.
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
121212© 2004, Cisco Systems, Inc. All rights reserved.
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
141414© 2004, Cisco Systems, Inc. All rights reserved.
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
161616© 2004, Cisco Systems, Inc. All rights reserved.
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
181818© 2004, Cisco Systems, Inc. All rights reserved.
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Example of Architecture Configuration and Cable Distances
191919© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idTypes of Ethernet
202020© 2004, Cisco Systems, Inc. All rights reserved.
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.
212121© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idParameters for Gigabit Ethernet Operation
222222© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idEthernet Frame
232323© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idOutbound (Tx) 1000Base-T Signal
242424© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idActual 1000Base-T Signal Transmission
252525© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idBenefits of Gigabit Ethernet on Fiber
262626© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idGigabit Ethernet Layers
272727© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.id1000BASE-SX and LX
282828© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idGigabit Ethernet Media Comparison
292929© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idGigabit Ethernet Architecture
Maximum 1000BASE-SX Cable Distances
Maximum 1000BASE-LX Cable Distances
303030© 2004, Cisco Systems, Inc. All rights reserved.
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).
313131© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idParameters for 10-Gbps Ethernet Operation
323232© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.id10GBASE LX-4 Signal Multiplexing
333333© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.id10-Gigabit Ethernet Implementations
343434© 2004, Cisco Systems, Inc. All rights reserved.
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
353535© 2004, Cisco Systems, Inc. All rights reserved.
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.
363636© 2004, Cisco Systems, Inc. All rights reserved.
www.pnj.ac.idSummary