Hub, switch, router, bridge & and repeater

This note contains a detailed description of Hub, Switch, Router, Bridge, and Repeater.

1. Pranab Bandhu Nath
(Senior Lecturer)
Department of CSE
City University, Dhaka.
Name : Maksudujjaman
ID : 1915002517
Batch : 50
th

Semester : Summer’21
Program : B.Sc. in CSE
Submitted By :
CITY UNIVERSITY
Faculty of Science and Engineering
Department of Computer Science & Engineering
CSE 317 Computer Networks, Summer’21
Supervised By :
This note contains detailed description about Hub, Switch, Router, Bridge and Repeater

Course Code: CSE 317
Course Title : Computer Networks
ABSTACT:

2. Hub, Switch, Router, Bridge and Repeater

Hub:

A hub is basically a multiport repeater. A hub connects multiple wires coming from different branches, for
example, the connector in star topology which connects different stations. Hubs cannot filter data, so data
packets are sent to all connected devices. In other words, the collision domain of all hosts connected through
Hub remains one. Also, they do not have the intelligence to find out the best path for data packets which leads
to inefficiencies and wastage.


Types of Hub-

o Active Hub:
These are the hubs that have their own power supply and can clean, boost, and relay the signal along
with the network. It serves both as a repeater as well as a wiring center. These are used to extend the
maximum distance between nodes.

o Passive Hub :
These are the hubs that collect wiring from nodes and power supply from the active hub. These hubs
relay signals onto the network without cleaning and boosting them and can’t be used to extend the
distance between nodes.

o Intelligent Hub :
It works like active hubs and includes remote management capabilities. They also provide flexible
data rates to network devices. It also enables an administrator to monitor the traffic passing through
the hub and to configure each port in the hub.

3. Switch:

Switch is a network device that connects other devices to Ethernet networks through twisted pair cables. It
uses packet switching technique to receive, store and forward data packets on the network. The switch maintains
a list of network addresses of all the devices connected to it.
On receiving a packet, it checks the destination address and transmits the packet to the correct port. Before
forwarding, the packets are checked for collision and other network errors. The data is transmitted in full duplex
mode










Data transmission speed in switches can be double that of other network devices like hubs used for networking.
This is because switch shares its maximum speed with all the devices connected to it. This helps in maintaining
network speed even during high traffic. In fact, higher data speeds are achieved on networks through use of
multiple switches.




Router:

A router is a device like a switch that routes data packets based on their IP addresses. The router is mainly a
Network Layer device. Routers normally connect LANs and WANs together and have a dynamically updating
routing table based on which they make decisions on routing the data packets. Router divide broadcast domains
of hosts connected through it.

4. Brouter:

It is also known as bridging router is a device which combines features of both bridge and router. It can work
either at data link layer or at network layer. Working as router, it is capable of routing packets across networks
and working as bridge, it is capable of filtering local area network traffic.


Bridge:

Bridge is used to divide a large network into smaller segments. Basic functions of the Bridge are the following:
o Breaking a large network into smaller segments.
o Connecting different media types. Such as connects UTP with the fiber optic.
o Connecting different network architectures. Such as connects Ethernet with the Token ring.

5. A Bridge can connect two different types of media or network architecture, but it cannot connect two different
types of network layer protocol such as TCP/IP or IPX. Bridge requires the same network layer protocol in all
segments.
There are three types of Bridge:

Local Bridge: This Bridge connects two LAN segments directly. In Ethernet Implementation, it is known as the
Transparent Bridge. In Token Ring network, it is called the Source-Routed Bridge.
Remote Bridge: This Bridge connects with another Bridge over the WAN link.
Wireless Bridge: This Bridge connects with another Bridge without using wires. It uses radio signals for the
connectivity.



Repeater:

A repeater operates at the physical layer. Its job is to regenerate the signal over the same network before the
signal becomes too weak or corrupted so as to extend the length to which the signal can be transmitted over the
same network. An important point to be noted about repeaters is that they do not amplify the signal. When the
signal becomes weak, they copy the signal bit by bit and regenerate it at the original strength. It is a 2 port
device.

6. References:
https://www.geeksforgeeks.org/network-devices-hub-repeater-bridge-switch-router-gateways/
https://afteracademy.com/blog/what-are-routers-hubs-switches-bridges
https://www.edupointbd.com/network-devices-ev/