Devices used in Networking:-
HUB:- Hub is centralized device, which is used to connect multiple workstations.It has no special kind of memory. It simply receives the frame (data) and forwards it to all its nodes except the receiving node. It always performs broadcasting. In case of hub, there is one collision domain and one broadcast domain. The media access method is used CSMA/CD (Carrier Sense Multiple Access/Collision Detection).
There are two types of Hub: -
- Active Hub
- Passive Hub
Active Hub:- In Active hub, it receives the frame regenerate
and then forward to all its nodes. It increases the distance between devices,
and it amplifies the signal and also the noise with it.
Passive Hub:-In Passive hub, it simply receives
the frame and forward to all its connected nodes. It reduces the cabling
distance by half because it doesn’t boost the signal and in fact absorbs some of
the signal.
SWITCH:- Switch
is also used to connect multiple workstations. Switch is more intelligent than
hub. It has special kind of memory called mac address/filter/lookup table.
Switch reads mac addresses. Switch stores mac addresses in its filter address
table. Switch when receives frame, it reads the destination mac address and
consult with its filter table. If he has entry in its filter table then he
forwards the frame to that particular mac address, if not found then it performs
broadcasting to all its connected nodes.
Every port has its own buffer memory. A port has two
queues one is input queue and second is output queue. When switch receives the
frame, the frame is received in input queue and forward from output queue. So
in case of switch there is no chance or place for collisions. In case of switch, the media access
method is used CSMA/CA (Carrier Sense Multiple Access/ Collision Avoidance).
Switches provide more efficiency, more speed and security.There are two types of switches: -
- Manageable switches (can be configured with console cable).
- Non-manageable switches.
BRIDGE:- Bridge is a hardware device, which is used to provide LAN segmentation means it is used for break the collision domain. It has same functionality as performed by switch. We can use bridge between two different typologies. It has fewer ports. Each port has a own buffer memory. It works on Data Link Layer of OSI model. It also read mac address and stores it in its filter table. In case of bridge there is one broadcast domain.
ROUTER:-Router is hardware device, which is used to
communicate two different networks. Router performs routing and path
determination. It does not perform broadcast information. Routers learn remote network information from neighboring router.Router then build routing table, which is basically map of interconnected network & it describe how to find remote network.
LAN CARD:- Lan card is media access device. Lan
card provide us connectivity in the network. There is a RJ45 (Registered Jack)
connector space on the Lan card. RJ45 is used in UTP cable. There is another
led which is also called heartbeat of Lan card. When any activity occur it may
be receiving or transmitting any kind of data. This led start blinking and also
tell us the status of lan card.
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