CS601 - Data Communication - Lecture Handout 43

User Rating:  / 0
PoorBest 

Related Content: CS601 - VU Lectures, Handouts, PPT Slides, Assignments, Quizzes, Papers & Books of Data Communication

Ethernet

Ethernet

10 Base 2: Thin Ethernet

  • The second Ethernet Implementation defined by IEEE 802 series is called 10 Base 2, Thin Ethernet, Thin net
  • Also called Cheap net because it provides an inexpensive alternative to 10 Base 5 Ethernet, with the same data rate
  • Like 10 Base 5, 10 Base 2 is a Bus Topology LAN
  • 10 Base 2: Thin Ethernet

The advantages of thin Ethernet are :

  • reduced cost and
  • ease of installation

Because the cable is lighter weight and more flexible than that used in Thicknet

The disadvantages are:

  • Short Range (185 m as opposed to 500 m)
  • Smaller Capacity (thinner cable accommodates fewer stations)

Physical Topology of 10 base 2

  • The connectors and cables utilized are: NICs, Thin coaxial cable and BNC-T connectors
  • In this technology, the transceiver circuitry is moved to the NIC, and transceiver tap is replaced by connector that splices directly into the cable
  • No AUI cables are needed

Physical Topology of 10 base 2

  • NIC
    • NICs in Thin Ethernet provide the same functionality as those in Thicknet plus the functions of the Transceiver
    • A 10 Base 2 NIC not only provides the station with an address but also checks for voltages on the link
  • RG-58 Cable
    • These cables are relatively easy to install and move around
    • Especially inside the buildings where cable must be pulled through the walls and the ceilings
  • BNC-T
    The BNC-T connector is a T-shaped device with three ports:
    • One for the NIC
    • One each for the input and output ends of the cable

10 base T: Twisted Pair Ethernet

  • Most popular standard defined in IEEE 802.3 series is 10 Base T also called Twisted Pair Ethernet
  • It is a Star topology LAN that uses Unshielded Twisted pair (UTP) cable instead of coaxial cable
  • It supports a data rate of 10 Mbps and has a maximum length of 100 meters

10 base T: Twisted Pair Ethernet

  • Instead of individual transceivers, 10 Base T Ethernet places all of its networking operations in an intelligent Hub with a port for each station
  • Stations are linked into the hub by four pair RJ-45 cable terminating at each end in a male-type connector much like a Telephone jack
  • The hub fans out any transmitted frame to all of its connected stations
  • Each station contains a NIC
  • A 4-pair UTP of not more than 100 meters connects the NIC to the appropriate port in 10 Base T Hub
  • The weight & flexibility of the cable and the convenience of RJ-45 jack and plug makes it the easiest to install and reinstall

1 Base 5: STAR LAN

  • Star LAN is infrequently used nowadays because of its slow speed of approx. 1Mbps
  • Range can be increased by DAISY CHAINING
  • Like 10 Base T, Star LAN uses Twisted pair cable to connect stations to a central hub
  • Star LAN allows 10 devices to be linked with only the lead device connected to the hub

1 Base 5- STAR LAN

Switched Ethernet

  • An attempt to improve the performance of 10BASE-T
  • N ×10 Mbps with N devices

Switched Ethernet

Fast Ethernet

  • Data rate can be increased by decreasing the collision domain
  • If 10 Mbps ⇒ 100 Mbps, then
    • 2500 m ⇒ 250 m

Fast Ethernet

100 Base-TX and 100 Base-FX

100 Base-TX and 100 Base-FX

100 Base-T4

100 Base-T4

Gigabit Ethernet

  • Usually serves as a backbone
  • Four implementations
    • 1000Base-SX, 1000Base-LX: Optical fiber, 550-5000 m
    • 1000Base-CX (STP), 1000Base-T (UTP): 25 m

Gigabit Ethernet

Token Bus

  • Other LANs are not suitable for this purpose
  • Token Bus has no commercial application in data communications
  • Token Ring allows each station to send one frame per turn
  • Access method: Token passing

Summary

  • Ethernet
    • Implementations
  • Other Ethernet Networks
  • Token Bus/Ring

Reading Sections

Section 12.2, 12.3, 12.4, 12.5
“Data Communications and Networking” 4th Edition by Behrouz A. Forouzan