Comparison Of Various Switching Techniques and Comparison Of Various Topologies

Comparision Of Various Switching Technniques:

Circuit Switching	Packet Switching	Message Switching
Circuit switching as a dedicated path transmission.	Packet switching does not have any dedicated path transmission.	Similar to packet switching their no dedicated path transmission in message switching.
Their will be call setup delay.	It has message transmission delay.	It has packet transmission delay.
In Circuit switching messsage is not stored.	In packet switching message is stored.	In message switching message is stored for short time.
In this blocking may occur.	In this blocking may not occur.	In this blocking may not occur.
In this user is  responsible for message-loss protection.	Network responsible for message-loss.	Network responsible for each packet but not for entire message.
Continous transmission of data.	Transmission of message.	Transmission of packets.
It operates in real-time.	It will not operates in real time.	It will operate nearly real-time.
It has fixed bandwidth.	It has dynamic bandwidth.	It has dynamic bandwidth.
It has busy signal.	Their no busy signal.	There is no busy signal.
There is no overhead bits after intial setup delay.	Overhead bits in each message.	Overhead bits in each packet.
In this path is established for entire message.	In this route is established for each message.	In this route established for each packet.
Speed is less.	Speed is more.	Speed is more.

Comparison Of  Various Topologies:

Specifications	Bus	Star	Ring
Network robustness	Low	Moderate	Low
Installation cost	Low	Moderate	Low
Each node failures	Whole network will not get effected only failure node is disconnected.	Whole network will not get effected only failure node is disconnected.	Whole network is failure.
Fault detection	Difficult	Easy	Difficult
Device adding	Easy	Easy	Easy
Reconfiguration	Easy	Easy	Difficult
Connection media	Optical fibre or coaxial cable.	Twisted pair	Optical fibre or coaxial cable.

Definition of Bandwidth and throughput:

Bandwidth:

When a channel can transmit a range of frequncies occupied by a signal is called bandwidth in herz. For example bandwidth of a telephone subscriber is 5 Khz. Or number of bits transmitted for second is called bits in seconds. Let’s consider a bandwidth of ethernet network is 100 mhz.

Throughput:

Throughput is defined as how fast useful information transmitted per unit time through the network. It is always less than channel bandwidth.