This document discusses various interconnection devices used in modern networks. It describes network interface cards (NICs), repeaters, hubs, bridges, switches, and routers. NICs allow devices to connect to networks and have a unique MAC address. Repeaters amplify signals to extend distances between nodes. Hubs connect devices but are simple and not used in wireless networks. Bridges filter traffic between network segments. Switches inspect and forward data at the data link layer. Routers connect multiple networks as layer 3 gateways and use routing tables to filter incoming and outgoing traffic.

2. • Many interconnection device are required
in a modern network, from the interface
that allows a single computer to
communicate with other computers via a
LAN cable or a telephone line, to the large
and complex switching devices that
interconnect two or more entire networks.

3. interconnection device
•
•
•
•
•
•
Network interface card
Repeater
Hub
Bridge
Switch
Router

4. Network Interface Card (NIC)

5. • Every device on a network that needs to
transmit and receive data must have
a network interface card (NIC) installed.
• They are sometimes callednetwork
adapters, and are usually installed into
one of the computer's expansion slots in
the same way as a sound or graphics
card.

6. • The NIC includes a transceiver, (a transmitter
and receiver combined).
• The transceiver allows a network device to
transmit and receive data via the transmission
medium.
• Each NIC has a unique 48-bit Media Access
Control (MAC) address burned in to its ROM
during manufacture.
• A MAC address is usually shown in hexadecimal
format, with each octet separated by a dash or
colon, for example: 00-90-47-03-B6-C4.

7. Repeater

8. • A repeater is a physical layer (OSI model)
device that amplifies the signal of one
segment onto one or more other
segments.
• Repeaters are used to extend the
maximum possible distance between end
nodes on a segment.
• They are completely transparent to the
sending and receiving nodes.

9. HUB
• A hub is used in a wired network to
connect Ethernet cables from a number of
devices together.
• The hub allows each device to talk to the
others. Hubs aren’t used in networks with
only wireless connections, since network
devices such as routers and adapters
communicate directly with one another.

10. • Hubs are such simple devices – they
require no configuration, and have no
manuals – that their function is now
included in other devices such as routers
and modems.

11. Bridge

12. • A bridge device filters data traffic at a
network boundary.
• Bridges reduce the amount of traffic on a
LAN by dividing it into two segments.
• Bridges operate at the data link layer
(Layer 2) of the OSI model

13. Switch
• A network switch is a small hardware
device that joins multiple computers
together within one local area network
(LAN).
• Network switches operate at layer two
(Data Link Layer) of the OSI model.
• Switches, unlike hubs, are capable of
inspecting data as messages are received
via a method called packet switching.

15. Router
• Routers are small physical devices that
join multiple networks together.
• Technically, a router is a Layer
3 gateway device, meaning that it
connects two or more networks and that
the router operates at the network layer of
the OSI model.

16. • By maintaining configuration information in
a piece of storage called the routing table,
wired or wireless routers also have the
ability to filter traffic, either incoming or
outgoing, based on the IP addresses of
senders and receivers.

18. REPEATER
T
C
H
ROUTER
S
W
I
G
A
T
E
W
A
Y