Ethernet LAN Topologies

Ethernet
Ethernet is the most popular LAN technology. It can support verity of media like copper (UTP, Coaxial, fiber optic). This technology supports wide range of speed from 10mbps to 10000 mbps.


Ethernet at Logical Link Control
To create logical link control Ethernet uses ARPA protocol also called IEEE802.3. Ethernet adds source MAC, destination MAC, error checking information and some other information to data. Ethernet encapsulation explain as follows .

 In these days, we use Ethernet with switches and in switches the technology is made CSMA/CA (Collision Avoidance). So this reason Ethernet is best compare with Token Ring, FDDI & Wi-Fi.

Back off Algorithm
This algorithm runs when a collision created.

Ethernet Family
Speed                        Base band
10                                 Base 2                200-meter                 Coaxial cable
10                                Base 5                 500-meter                 Thick Coaxial cable
10                                Base T                 100 meter                  Twisted Pair (UTP)
10/100                      Base TX              100 meter                   UTP
100                             Base T4              100 meter                   UTP 4 Pairs used
100                             Base FX              up to 4 kms                Fiber Optic
1000(Server)         Base TX              100 meter                   UTP
1000                          Base FX               up to 10 kms             Fiber Optic
10000                        Base FX                                                      Fiber Optic

Ethernet Cabling

Coaxial cabling 

Requirement: - T connector, Terminator, BNC connector, Coaxial cable, 10 base2 lan cards

This is used by BUS topology with 10 mbs Base 2 and Base 5. it is not used currently.
UTP Cabling - In the UTP, we have used different topology to create the network.

In any Ethernet UTP topology we have to use one of the two types of cables

1. Straight cable
2. Cross cable

TX
RX
Structure Cabling  Requirement: - Rack, patch panel, Switch/ Hub( Rack Mounable), patch cord, I/O connector, I/O box, UTP cable .
Tool: - Punching tool

Problems of Ethernet technology

1. In Ethernet only one pc is able to send data at a time, due to this the bandwidth of Ethernet will be shared.
2. Not an equal access technology.
3. One pc will send data, which will be received by the all devices of network. Due to this data communication will not be secured.
4. Collision will occur in the network and collision will lead to other problems like latency, delay and reduce throughput. 
5. All PCs will have single broadcast domain. Due to this the bandwidth will be reduced.

                        EMI – Electro Magnetic Indication

     

Posted in: CCNA