This Document content the different networking devices, their advantages & disadvantages etc.

1. 1
Table of content:
 Routers 2
 Gateway 3
 Switch 5
 Bridge 6
 Repeaters 8
 Reference 9
 Turnitin reports 10

2. 2
 Router
Introduction
From the view point of networking, Routers is more intelligent, sensitive
protocol linking small device which is especially used to link separate network and
provide access of internet to the users. Similarly, Due to its capability of working at the
layer 3 of OSI Layer it is more complicated than any other exiting networking devices.
Specially routers can be a hardware, software or both which can connect two different
networks such as (a) Ethernet to Ethernet , (b) token ring to Ethernet, (c) MAN to WAN.
As a result, the routers are similar to bridge and networking HUB but in fact there is
incomparable difference between them and routers are more function able.
Advantages:
We know routers works at the third layer of OSI Model it is basically used
for communication which include the internet. Likewise, Routers find the shortest and the
easiest path to transfer the data, information between the different sending and receiving
computers without any disturbance. During the addressing of the data routers uses the IP
Addressing for accessing and also for forwarding the data in the one hand. On the other
hand, routers manage or provide the alternative solution for the broadcast problems as it
break the networks into many broadcast domain. Similarly, without using MAC address it
implement quality of service using traffic shaping, protecting traffic by using encryption
and filtering the traffic by Access Control List.

3. 3
Disadvantages:
Leaving the advantages of the routers there we can find some
disadvantages also. Typically in case of performance speed, system cost, and working
protocol. In case of static routing the users of the networks administrator must update the
routing table manually but this is automatically update during the data transfer process
between different computers in dynamic routing. Similarly as compare to the price of the
routers it is more expensive than other networking devices. Basically the performance
speed is quite slow than that of bridge because of its complex calculation in network
layer. Finally its works with some specific protocols like TCP/IP, DECnet, OSI, XNS,
IPX/SPX etc.
Function: Some of the function of routers is listed below:
 Removal of corrupt packets or data
 Interconnection between different networks architectures, physical
media etc.
 Provide a suitable path for packets transfer
 Performs complex mathematical calculations
Conclusion:
Apart from the advantage and disadvantage of the routers we came to the
conclusion that it is able to reduce the traffic in the network by avoiding corrupt data &
transferring data to the destination through the suitable path.
 Gateway
 Introduction:
A networking device which is used to link the different LANs. It can
perform the overall function of bridge & routers and also capable to converts the
entire protocol of different networks. On the other hand gateway operates at all the
seven layer of OSI model. Hence, it is good protocol converter.

4. 4
Reasons and Advantages:
Unlike the routers that performs at the network layer of the OSI model
which is able to accepts, relays & transfers of packets only under the network using
the same protocol. But a normal gateway is able to convert a packet designed for one
protocol to different existing protocol e.g. in case of connection of Token ring with
Ethernet, the gateway also converts the Token ring protocol to Ethernet protocol. It
works as a server for other server because it can understand the protocol used by each
of the network link into the routers & able to translate it into others protocol.
Disadvantages:
Generally a normal gateway used in the connection between the dissimilar
LANs is software installed on a router. Therefore, it is very much expensive in cost as
similar as router. As a gateway is a pre-installed software programmer in a router it is
more difficult to network user to install it or configure it without any knowledge. Due
to the complex conversion process & greater requirement a gateway is slower than
other devices such as bridge & routers.
Function:
As moving deeply in the complex function that the gateway performs is
task dedication. Gateway is completely dedicated to the specific task at once &
contributes to complete the task very well. And the another function that a gateway
play is the interconnection between the completely different system together.
Likewise, the main & important function of the gateway is protocol conversion. i.e. a
gateway can control the entire protocol of a network to other.
Conclusion:
Gateway is an internetworking device but it can perform the whole
function which is performed by the interworking bridge and routers. Gateway works
on the seven different layer of OSI model & are often used as server-side portals
through network firewalls & also used as the translators for access to the resources
stored on http system. Hence, protocol conversion is the wise part which is
particularly handled by gateway.

5. 5
 Switch:
Introduction:
The foundation of the communication link between the two different nodes
is noticed as switching. And the device which is used is known as switching & the
system is called switching system. The work at the data link layer of OSI model.
Typically, the switches are made to solve the problems regarding the bandwidth &
collision in the networks. With the help of ASICs they make their switching decision
in hardware.
Reasons and Function:
During the process of switching the frame in hardware, the switch may
utilize multiple methods of switching which supports half-duplex or full-duplex
connection with hundreds of ports. The main function is to switch the frame very fast.
Here, switch learns MAC address statically or dynamically in CAM table & forward
the frame very intelligently without high traffic. Similarly we can configure different
ports of different speed at the switch.
Advantages:
Besides solving the collision & the bandwidth problems switch is able to
perform the full-duplex at all the ports & established the dedicated connection within
a routers, PC or the server. Similarly a switch can frame very fast up to the speed of
50,000 per second where we can create a dedication for special ports i.e.,
simultaneous or multiple session transmission between the ports.
Disadvantages:
As we already know switch play a vital switching role in the hardware with
the help of application specific integrated circuits(ASICs) which is a very especial
processor designed to perform a very few specific task. Hence ASICs are very
expensive or costly as compare to the normal processor. The cut-through switching is
only usable if the vendor has included it in its switching product. If the vendor is
without dynamic switching there may be the problems switching the bad frame. Since
the header could readable but remaining frame are corrupted due to collision. Hence
dynamic switching reduces the problems of switching the bad frame.

6. 6
Conclusion:
Finally, switch is similar to bridge but in facts there is a huge difference
between them. Generally switch switches the frame very fast & tries to control the
problems of collision & bandwidth. Hence by implementing the entire three methods
(cut-through, fragment-free & store and forward) switch is able to switch the frame at
a rate of 50,000 & more per seconds.
 Bridge:
Introduction:
Bridge is a networking device which normally works in the physical and
data link layer of OSI model. It is capable of connecting two network segments
and transferring data between them by using the same protocol. Bridge can also
be used as connecting device between the different HUBs that is to say it is
capable of connecting different HUB.
Reasons:
Especially bridge is a store & forward device. During the connection of
different LANs it receives the frame from one LAN and transfer the same frame
without encapsulating or without modification to other LAN. By using local and
remote bridge a network administrator can easily extend the network distance i.e.
local bridge link the LAN separated by small distance whereas remote bridge link
the LAN separated by large distance.

7. 7
Advantages:
As bridge can work in the data link layer it must be capable of handling
physical addressing. As compare to broadcasting HUB it is more intelligent
because bridge maintain the physical address tables and transfer the data with the
help of receiving and sending computers MAC address. During this process it
reduces the unnecessary traffic problems by controlling broadcasting. Similarly
by implementing remote bridge network distance can be extended because remote
bridge link the different LAN separated by large space. Meanwhile a normal
bridge can connect different media within the same network whereas a translation
bridge can link the different architecture of the networks.
Disadvantages:
Leaving the advantage of the bridge some sort of disadvantage can be
found on the bridge. The speed is slower than the repeaters but it is fast than that
of the routers. Likewise comparing the cost it is expansive than repeaters but a bit
cheaper than the routers. And the main disadvantage is that it is not able to handle
the multiple paths.
Functions:
Apart from the learning, forwarding and removing loop function of bridge
there are some more function listed below
 Solve the problems of collision and bandwidth.
 Able to connect different media with the networks.
 Network traffic reduction.
 Use MAC table during the data transmission.
 Can link two similar networks together.
Conclusion:
Among the four different types of bridge translation can link (Ethernet to
Token ring) different architecture together. Hence in the data link layer bridge can
access to information because of the physical address of both source and
destination computer. Finally it decides whether to forward data or not to forward
it.

8. 8
 Repeaters:
Introduction:
Another mostly used network connecting device is repeater. In the OSI
layer, repeater work at the first physical layer. It is a low-level device of
transparent nature it cannot distinguish between the data and noise. When there is
noise in the process of communication it amplifies with the data. So repeater is a
signal amplifier used to amplify the low signal to high signals.
Advantages:
At the physical layer where the repeaters allow the users to extend the
physical length of networks. That is to say repeaters expand the network over the
large distance by using remote repeaters. Also a repeater can link the various
Ethernet segments of any media type and it is capable of amplifying the signals
before the signals became weak.
Disadvantages:
Working in the physical layer they are not able to known the type of date
transferring, different
Address and protocol used so they are called unintelligent electronic device that
cannot filter and
Translate the information or message. Next the location of repeaters also plays a
huge role because
Noise can alter the data and initial data becomes unrecoverable. But the number
of repeaters used
Must be least in order to avoid the propagation delay. Hence network
architectures maintain the
Limited repeaters in their network. And the other disadvantage of repeaters is that
it cannot connect
The network of two different architecture such as Token ring and Ethernet etc.

9. 9
Functions: The major function of repeaters is as listed below:
 It amplifies the signals without impacting the speed of the networks.
 Network administrator can expand the network into large distance with the help of
repeater.
 Concerning the location of repeaters used the signals can be refreshed back
without any noise and delay.
Conclusion:
Finally, repeaters are an unintelligent connecting device which operates in
the physical layer and contribute to amplifying the data before the signals became weak
and noisy.
Reference:
 Essential of networking and network security (CNW101)
 Computer Science (Author:Juddha Bahadur Gurung, Niraj Baral
Publication:Bhudipuran publication Nepal)
 Computer Networking (C1006)

10. 10
Turnitin Reports:
Turnitin Originality Report
Networking Devices by Anit Thapaliya
From Networking Devices (CNW101_DEC_2011)
 Processed on 02-23-11 8:48 PM PST
 ID: 172905169
 Word Count: 1935
Similarity Index
1%
Similarity by Source
Internet Sources:
0%
Publications:
0%
Student Papers:
1%
sources:
1
1% match (student papers from 02/11/07)
Submitted to Franklin University on 2007-02-11
2
< 1% match (student papers from 05/03/02)
Submitted to Rose-Hulman Institute of Technology on 2002-05-03