The document explains computer networking, detailing components such as repeaters, bridges, routers, hubs, and switches. It highlights the functions of these devices, including data transmission, traffic management, and efficiency improvements in network communication. The comparison of hubs and switches shows how switches enhance network performance by targeting specific destination addresses.

1. The Concept of Networking

2. Networking
 A computer network is a series of
computers and other devices
interconnected by communication
paths.
 Computer networks include: LANs
and WANs

3. Networking
 A network consist of two computers
connected to each other by a cable so
that can share data.

4. Network Devices
 The components that enable
engineers to accomplish these goals
are
 Repeaters
 Bridge
 Routers
 Hub

5. Repeaters
 Repeaters regenerate weakened
signals

A repeater takes a weak signal from one
segment, regenerates it, and passes it to the
next segments.

Join two separate LANs

Connect to other LANs and computing
environments to join them in to a larger
network.

6. Repeaters
 Do not use a repeater when
 There is heavy network traffic
 You need any kind of data filtering

7. Bridge
 A bridge goes one step up on a hub
in that it looks at the destination of
the packet before sending. If the
destination address is not on the
other side of the bridge it will not
transmit the data.
 A bridge only has one incoming and
one outgoing port.

8. Bridge

9. Bridge
 Bridge connecting two network Bridges
can be used to
 Expand the distance of segment
 Provide for an increased number of
computers on the network
 A bridge can take an overloaded network
and split it into two separate networks
reducing the amount of traffic on each
segment and making each network more
efficient.

10. How Bridges work
 Listen to all traffic
 Checks the source and destination
addresses of each packet
 Builds a routing table as information
becomes available
 A bridge forwards packets based on
the address of the destination

11. Router
 Router is a communication device
that connects multiple computers . All
sizes of networks use routers.
 Many routers are protected by built-
in firewall s. Some also have built-in
antivirus protection.

13. Routers
 They only understand network
numbers or network address. Router
will only pass information if the
network address is known.
 This ability to control the data passing
through the router reduces the amount
of traffic between networks and allows
routers to use these links more
efficiently than bridges.

14. Router
 A device that forwards data packets
along networks. A router is
connected to at least two networks,
commonly two LANs or WANs or a
LAN . Routers are located at gateways
, the places where two or more
networks connect.

15. Router
 Routers use headers and forwarding
tables to determine the best path for
forwarding the packets, and they use
Protocols .

16. Hub
 Hub is a central component .Signals are
transmitted from the sending computers
through the hub.
 Hubs usually have eight to twelve ports for
network computers to connect to, they are
sometimes called multiports repeaters.
 Hub is an unintelligent device.
 Every time broadcasting device
 . Its job is very simple: anything that comes

17. Hub

18. Hub
A hub is the simplest of these
devices. Any data packet
coming from one port is sent
to all other ports. It is then up
to the receiving computer to
decide if the packet is for it.

19. Hub
 Imagine packets going through a hub
as messages going into a mailing list.
The mail is sent out to everyone and
it is up to the receiving party to
decide if it is of interest.

20. Hub
 Hubs are typically used on small
networks where the amount of data
going across the network is never
very high.

21. Hub
The biggest problem with hubs is
their simplicity. Since every
packet is sent out to every
computer on the network, there
is a lot of wasted transmission.
This means that the network can
easily become bogged down.

22. Switche

23. Switches
Switches are a special type of
hub that offers an additional
layer of intelligence to basic,
physical-layer repeater hubs.
A switch must be able to read
the MAC address of each
frame it receives.

24. Switches
This information allows
switches to repeat incoming
data frames only to the
computer or computers to
which a frame is addressed.
This speeds up the network
and reduces congestion.