DEPARTMENT OF ELECTRONIC & TELECOMMUNICATIONN ENGINEERING
MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO
COMPUTER COMMUNICATION & NETWORKING
________________________________________________________________________
Name: _____________________________________________ Roll No: _____________
Score: ____________Signature of the Lab Tutor: _______________ Date: ___________
________________________________________________________________________
NETWORKING TOPOLOGY
PERFORMANCE OBJECTIVE
Upon successful completion of this experiment, the student will be able to:
(i)
(ii)
Carrying out a LAN with star topology
Use of TRANSCEIVER_RJ45 for UTP cable (10 base T)
EQUIPMENT








PC_SERVER
PCs_CLIENT
ETH_CARD
HUB_10
TRANSCEIVERs
Patch –cords RJ45-RJ45
G_FLOOR and F_FLOOR
Cabling & Transceiver panel.
DISCUSSION
A network technology is composed of different active and passive elements. The modes
with which these elements are interconnected are identified as network architecture or
topology.
STAR TOPOLOGY
The star network configuration is the most popular topology. As fig shows, in a star
configuration all computer or stations are wired directly to a central location, which is
usually a hub or a Multistation Access Unit (MAU). A data signal from any station goes
directly to this central device, which h transmit the signal according to the established
network access method for the type of network
Advantages
 A break in one cable does not affect all other stations as in bus technologies
because there is only one station per segment. This means the star is generally
more reliable
 In a star, problems are easier to locate because symptoms often point to one
station
 The star is the second-easier topology to design and install, after the bus
DEPARTMENT OF ELECTRONIC & TELECOMMUNICATIONN ENGINEERING
MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO
COMPUTER COMMUNICATION & NETWORKING
________________________________________________________________________
 The star does not require manual termination. Instead, the media is terminated in
the station at the transceiver on the network interface card (NIC) and in the hub or
MAU.
Disadvantages
 Hubs, which are required for the star, are more expensive than bus connectors
 A failure at the hub can affect the entire configuration and all connected stations
 Star topologies use more cable than bus topologies because separate wire run to
each individual station.
TRANSCEIVER
The Transceiver is the element enabling the transmission/reception of the packets
between the AUI interfaces of the NIC (Ethernet controller) and the transmission mean.
This component typically used in Ethernet networks is carried out with yellow coaxial
cable (Thick Ethernet), but it is often employed also to convert the format of the signal
between the AUI interface and the other transmission means (twisted pair, thin coaxial
cable, optical fiber). The NIC card is connected to the transceiver via a drop cable. The
transceiver consists of:
 A transmitter sending data from the interface to the transmission mean
 A circuit for collision detection, sending the interface (card) a collision signal in
case this is occurred. The transceiver can also carry out the test to the interface.
This test can also be enabled or disabled (on the Transceiver) and can take
different names: Collision Present Test (CPT), Heartbeat (HUB), Signal Quality
Error_ test (SQE)
 A receiver for the data coming from the transmission mean and going to the
interface of the NIC card.
DEPARTMENT OF ELECTRONIC & TELECOMMUNICATIONN ENGINEERING
MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO
COMPUTER COMMUNICATION & NETWORKING
________________________________________________________________________
ETHERNET (10 BASET)
The most popular wiring schemes are 10BASE_T and 100BASE-TX, which use
unshielded twisted pair (UTP) cable. This is similar to telephone cable and comes in
variety of grades, with each higher grade offering better performance. Category 5 cable
the highest, most expensive grade, offering support for transmission rates of up to 100
Mbps. Category 2 and 3 cables are less expensive, but cannot support the same data
speeds; category 4 cable can support speeds up to 20 Mbps, and category 3 up to 16
Mbps. Category 1 and 2 cables are not used in the design of 10BASE-T networks.
Ideally, category 5 patch cables should be used in 10BASE-T(so that you can upgrade to
“Fast Ethernet” without re-cabling). 10BASE-T networks are wired (within the plugs and
ports) according to EIA and TIA 568 specifications. Maximum cable length is 100
meters.
PROCEDURE 1
The G_FLOOR must be cabled with a structured cabling system type UTP with all users
connected to the same floor closet.
Carry out the cabling as shown in fig: (Network installation diagram)
 Set a Hub_10 on the G_FLOOR in the floor closet and power it with the proper
power supply,
 Connect the PC_SERVER and the two PCs_CLIENT to the HUB_10 via a port
RG-45 of each ETH-CARD and 6 patch cord RJ45-RJ45, whenever the port 4 of
the HUB_10 is chosen, be sure that the switch MDI/X is disconnected,
 Check that the green LED of the ETH_CARD, and the used ports on the HUB_10
are on:
DEPARTMENT OF ELECTRONIC & TELECOMMUNICATIONN ENGINEERING
MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO
COMPUTER COMMUNICATION & NETWORKING
________________________________________________________________________
REVIEW QUESTIONS
1. Why STAR is considered as the most useful networking topology?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
2. How STAR topology is achieved and where you perform the termination?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
3. Which type of media and connector are used in STAR network?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
4. If you are intend to connect two Hubs which wiring scheme you should use and why?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
FINAL CHECK LIST
1. Return all equipment and materials to their proper storage area.
2. Submit your answers to question, before the next laboratory.