CISCO NETWORKING ACADEMY PROGRAM (CNAP) SEMESTER 1/ MODULE 7

1

CISCO NETWORKING ACADEMY PROGRAM (CNAP)SEMESTER 1/ MODULE 7

Ethernet Technologies

2

CISCO NETWORKING ACADEMY PROGRAMSEMESTER 1/ MODULE 7

Ethernet Fundamentals

Objectives

• Upon completion of this module, students will be able to perform tasks related to the following:

• 10-Mbps and 100-Mbps Ethernet

• Gigabit and 10-Gigabit Ethernet

3



Types of Ethernet

4



10-Mbps Ethernet

• 10BASE5, 10BASE2, and 10BASE-T all share the same timing parameters, as shown below

5



10-Mbps Ethernet

• The encoding technique used in 10-Mbps Ethernet is called “Manchester”

6



10BASE5

• 10BASE5 transmitted 10 Mbps over a single thick coaxial cable bus• Each of the maximum five segments of thick coax may be up to 500 m (1640.4 ft) in length• 10BASE5 only runs in half-duplex resulting in a maximum of 10 Mbps of data transfer• Figure shown below illustrates one possible configuration for a maximum end-to-end collision

domain• Between any two distant stations only three repeated segments are permitted to have stations

connected to them• with the other two repeated segments used only as link segments to extend the network.

7



10BASE2

• 10BASE2 transmitted 10 Mbps over a single thin coaxial cable bus• Each of the maximum five segments of thick coax may be up to 185 m in length• 10BASE2 only runs in half-duplex resulting in a maximum of 10 Mbps of data

transfer• There may be up to 30 stations on any individual 10BASE2 segment

• Out of the five consecutive segments in series between any two distant stations

• Only three may have stations attached

8



10BASE2

9



10BASE-T

• 10BASE-T used Category 3 unshielded twisted pair (UTP) copper but recommended that any new cable installations be made with Category 5e or better

• A 10BASE-T UTP cable has a solid conductor for each wire in the maximum 90 meter horizontal cable

• Originally 10BASE-T was a half-duplex protocol, but full-duplex features were added later

• 10BASE-T carries 10 Mbps of traffic in half-duplex mode and 20 Mbps in full-duplex mode

10



10BASE-T Wiring & Architecture

11



100-Mbps Ethernet• 100-Mbps Ethernet is also known as Fast Ethernet or IEEE 802.3u

• 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

• Two separate encoding steps are used by 100-Mbps Ethernet

• The first part of the encoding uses a technique called 4B/5B

• the second part of the encoding is the actual line encoding specific to copper or fiber

12



100BASE-TX

• 100BASE-TX using Cat 5 UTP cable

• 100BASE-TX uses 4B/5B encoding, which is then scrambled and converted to multi-level transmit-3 levels or MLT-3

• 100BASE-TX carries 100 Mbps of traffic in half-duplex mode.

• In full-duplex mode, 100BASE-TX can exchange 200 Mbps of traffic

13



100BASE-FX

• 100BASE-TX using Fiber Optic cable

• 100BASE-FX also uses 4B/5B encoding which called NRZI (Nonreturn to Zero Inverted) encoding

14



Fast Ethernet Architecture

• Fast Ethernet links generally consist of a connection between a station and a hub or switch

• A Class I repeater may introduce up to 140 bit-times of latency and is any repeater that changes between one Ethernet implementation and another

• A Class II repeater may only introduce a maximum of 92 bit-times latency

• Because of the reduced latency it is possible to have two Class II repeaters in series

15



1000-Mbps Ethernet

• The 1000-Mbps Ethernet, Gigabit Ethernet or IEEE 802..3z standards represent transmission using both fiber and copper media

• Fiber-based Gigabit Ethernet (1000BASE-X) uses 8B/10B encoding which is similar to the 4B/5B concept

• 1000BASE-TX, 1000BASE-SX, and 1000BASE-LX use the same timing parameters, as shown below

16



1000BASE-T• 1000BASE-T use all four pairs of wires (must meet the higher quality Category 5e or ISO

Class D (2000) requirements)

• The 1000BASE-T encoding with 4D-PAM5 (4-Dimensional 5 level Pulse Amplitude Modulation) line encoding

• In idle periods there are 9 voltage levels found on the cable, and during data transmission periods there are 17 voltage levels found on the cable

17



1000BASE-SX & LX

• 1000BASE-X uses 8B/10B encoding converted to non-return to zero (NRZ) line encoding

• The NRZ signals are then pulsed into the fiber using either short-wavelength or long-wavelength light sources:

• The short-wavelength uses an 850 nm laser or LED source in multimode optical fiber (1000BASE-SX)

• The long-wavelength 1310 nm laser source uses either single-mode or multimode optical fiber (1000BASE-LX)Laser sources used with single-mode fiber can achieve distances of up to 5000 meters

18



Gigabit Ethernet Architecture

• 1000BASE-SX

• 1000BASE-LX

19



10-Gbps Ethernet

• IEEE 802.3ae was adapted to include 10 Gbps full-duplex transmission over fiber optic cable

• As is typical for new technologies, a variety of implementations are being considered, including:

• 10GBASE-SR – Intended for short distances over already-installed multimode fiber, supports a range between 26 m to 82 m

• 10GBASE-LX4 – Uses wavelength division multiplexing (WDM), supports 240 m to 300 m over already-installed multimode fiber and 10 km over single-mode fiber

• 10GBASE-LR and 10GBASE-ER – Support 10 km and 40 km over single-mode fiber

• 10GBASE-SW, 10GBASE-LW, and 10GBASE-EW – Known collectively as 10GBASE-W are intended to work with OC-192 synchronous transport module (STM) SONET/SDH WAN equipment

20



10-Gbps Ethernet

21



10-Gbps Ethernet Implementations

Documents

CISCO NETWORKING ACADEMY PROGRAM (CNAP) SEMESTER 1/ MODULE 7