1. Packet Switched Networks (Chapter 11.1) by Beverley Louis

2. Packet Switched Networks (brief History)
During the Cold War in the late 1950's, the US Department of Defense was concerned about a nuclear war's effect on their communications systems.
Existing networks were point-to-point networks. Stations or nodes were linked to each other in a line or chain.

3. Data must travel through each node / Station to reach destination
Point-to-Point Network
Data must travel through each node / Station to reach destination
If one station was destroyed, the entire chain of nodes would not be able to communicate.

4. A researcher who worked for the military discussed the possibility of a 'decentralized network' where the network's nodes / stations each had multiple connections to each other, and there was no central node or server.
If a node /Station were destroyed, communications could be redirected through other nodes to reach the intended destination.
In 1969 the Pentagon's Advanced Research Projects Agency (ARPA) funded and developed this idea as the first packet-switching network.

6. How does it work ? dividing a message into tiny chunks, or packets.
each packet contains a
destination address.
packets are routed through
various paths within a
distributed network.
Packets move between
nodes quickly & arrive at
their destination within a
fraction of a second.

7. the network picks the best possible route for a packet to take through the network at any particular time thereby maximizing efficiency.
In the event of a node or path (link) failure. Packets are re-routed automatically, but the overall system is still operable.

8. The End Thank You