This document discusses different types of network switching: circuit switching, packet switching, and message switching. It describes circuit switching as establishing a dedicated electrical path for communication between two ports. Packet switching breaks communication down into small packets that are routed through the network based on destination addresses. There are two approaches for packet switching - datagram and virtual circuit. Datagram packets can take different paths to the destination while virtual circuit establishes a pre-planned route. Message switching does not establish a dedicated path, and each message is treated independently with the destination address added. The document was submitted by several students to their professor.
2. • Switching is a process moving data from one interface
and delivering it through another interface, selecting the
best paths between machines that stores messages.
• The fundamental purpose of a communication system is
to exchange information between two or more devices.
• A switched network consists of a service of interlinked
nodes called switches, switches are hardware and
software device capable of creating temporary
connections b/w two or more devices linked to a switch
but not to each other.
4. • Circuit switching is the dominant technology for both
voice and data communication.
• Communication via circuit switching in data
communication networks implies that there is
dedicated electrical, communication path between two
ports or hosts.
• The electrical path may be realized by physical wires
or co axial cables or radio or satellite communication.
• EX:-
Telephone network connection.
5.
6. • Packet-switched describes the type of network in which
relatively small units of data called packets are routed through
a network based on the destination address contained within
each packet.
• Breaking communication down into packets allows the same
data path to be shared among many users in the network.
• This type of communication between sender and receiver is
known as connectionless .
• The control information should at least contain:
– Destination Address
– Source Address
8. • In Datagram packet switching each packet is a self- contained unit
with complete addressing information attached.
• This fact allows packets to take a variety of possible paths
through the network.
• So the packets, each with the same destination address, do not
follow the same route, and they may arrive out of sequence at
the exit point node (or the destination).
• Reordering is done at the destination point based on the
sequence number of the packets.
9. •In the Virtual Circuit approach a pre-planned route is established
before any packet are sent.
•There is a call set up before the exchange of data.
•All packets follow the same route and therefore arrive in
sequence.
•Each packet contains a virtual circuit identifier instead of
destination address
•More set up time
•No routing decisions required for each packet - Less routing or
processing time
•Susceptible to data loss in the face of link or node failure
•Clear request to drop circuit
•Not a dedicated path
10. • A message is a logical unit of information and can be of
any length.
• In message switching, if a station wishes to send a
message to another station, it first adds the destination
address to the message.
• Message switching does not establish a dedicated path
between the two communicating devices i.e. no direct link
is established between sender and receiver.
• Each message is treated as an independent unit.