Network
Topology
Network topology refers to the layout of the computers and devices in a communications network.
A bus network consists of a single central
cable (backbone/trunk), to which all computers and
On a ring network, a cable forms a closed loop(ring)
with all computers and devices arranged along the ring.
How data transmit?
The
bus in a bus network transmit data, instructions, and information as a series
of signal.
Those
signals are sent as electrical pulses that travel along the length of the cable
in both directions.
How data transmit?
Data
transmitted on a ring network travels from device to device around the entire
ring, in one direction (clockwise or counterclockwise)
Token
passing is one method for sending data around a ring
How data transmit?
Two types
of devices that provide a common central
connection point to all the other devices on the network are a hub and a switch.
The device that provides a common central connection
point for other devices on a network.All data that transfers from one device to
another passes through the hub or switch.The hub takes a signal that comes from
any device and passes it along to all
the other devices in the network.
Advantages
1.
Bus networks are inexpensive and easy to install.
2.
Computers and other devices can be attached and detached at any point on the bus without disturbing
the rest of the network.
3.
Failure of one device usually does not affect the rest of the bus network.
Disadvantages
1.
There might be disruption when computer or other devices are added or removed.
2.
Because all systems on the network connect to a single cable or backbone, a
break in the cable will prevent all systems from accessing the network.
3.
It is difficult to identify the problem if the entire network shut down.
Advantages
1.
The transmission of data is relatively simple as packets travel in one
direction only.
2.
Cable faults are easily located, making troubleshooting easier.
3.
The uses of token passing enables all devices in a ring topology to share the
network resources
fairly.
1. A failure in any cable or device breaks the loop
and can take down the entire network.
2. Data packets must pass through every computer
therefore, this makes it slower.
3. A ring network can span a larger distance than a
bus network, but it is more difficult to install.
Advantages
1. If one device fails, only that device is affected.
2. Devices can be added to or removed from network
with little or no disruption.
3. Easy to troubleshoot and isolate problem.
Disadvantages
1. If the hub or switch fails, the entire network will
be inoperable.
2. Requires more cable than most of the other
topologies.
3. More expensive because of the cost of the
hub/switch.