1. By irwansyah and zulfakar
Star Topology
You will find that a star topology is most common in networks. This is
mainly because of the ease of configuring and troubleshooting it. If a
wire or a single port on the hub or switch goes bad, only one network
node goes down, which prevents a huge impact on productivity
overall (unless the entire hub or switch fails-in which case, the whole
LAN goes down). However, because a star topology involves a
central hub or switch as well as a lot more cabling, it costs more to
implement.
Disadvantages of a Star Network
Twisted pair cables typically used in star topologies are not as immune to interferences as coaxial
cable
Expensive because of additional cabling and central hub require
If the centralize device fails the entire system is affected
Advantages of Star Network
Easy to Install: Each device on network simply requires a cable run between it and the
concentrator device.
Flexible: Devices can be added or removed without affecting the other devices on the network.
A single device or cable failure will not bring down the network
Easy to set up and to expand as each device on the network simply requires a cable run
between it and the concentrator device
Any non-centralized failure will have very little effect on the network, whereas on a ring network
it would all fail with one fault.

2. Data Packets are sent quickly as they do not have to travel through any unnecessary nodes.
Performance is greater with speeds capable of 10mbps to 100mbps or more
The ability to isolate individual devices in troubleshooting An intelligent central hub or switch that
can help diagnose and manage the network Adjusting traffic levels so that computers that place
heavy loads on the network are moved to separate hubs
Bus topology
In bus topologies, all computers are connected to a single cable or "trunk or backbone", by a
transceiver either directly or by using a short drop cable.
The number of computers on a bus network will affect network performance, since only one
computer at a time can send data, the more computers you have on the network the more
computers there will be waiting send data. A line break at any point along the trunk cable will result
in total network failure. Computers on a bus only listen for data being sent they do not move data
from one computer to the next, this is called passive topology.
Disadvantages
Entire network shuts down if there is a break in the main cable.
Difficult to identify the problem if the entire network shuts down.
Performance: Coax technology is usually limited to a maximum of 10mbs.
Not intended for use as a standalone solution in a large building.
Coax technology is usually limited to a maximum of 10mbs.
Limited cable length and number of stations.
Not intended for use as a standalone solution in a large building.
If there is a problem with the cable, the entire network goes down.
Performance degrades as additional computers are added or on heavy traffic.
Low security (all computers on the bus can see all data transmissions).
If one node fails, the whole network will shut down.
You are limited with the number of devices that you can have on a single segme
Advantages
Inexpensive: Does not require additional hardware to interconnect the attached devices.

3. Easy to Install: Coax cable is durable and performs well in harsh environments.
Flexible: New devices can be added by simply installing a new ‘T’ connector.
Well suited for temporary or small networks not requiring high speeds(quick setup)Initially less
expensive than other topologies.
Requires less cable length than a star topology
Ring Topology
In a ring topology network computers are connected by a single
loop of cable, the data signals travel around the loop in one
direction, passing through each computer. Ring topology is an
active topology because each computer repeats (boosts) the
signal before passing it on to the next computer. One method of
transmitting data around a ring is called token passing. The
token is passed from computer to computer until it gets to a
computer that has data to send.
Advantages
Data is quickly transferred without a 'bottle neck'
The transmission of data is relatively simple as packets travel in one direction only.
Adding additional nodes has very little impact on bandwidth
It prevents network collisions because of the media access method or architecture required.
All devices have equal access.
Disadvantages
Because all stations are wired together, to add a station you must shut down the network
temporarily.
It is difficult to troubleshoot the ring.
Data packets must pass through every computer between the sender and recipient Therefore
this makes it slower.
If any of the nodes fail then the ring is broken and data cannot be transmitted successful

4. 4 W’s
What
Star
Involves a central a
star topology hub or
switch as well as a lot
more cabling, it costs
more to implement.
Bus
In bus topologies, all
computers are
connected to a single
cable or "trunk or
backbone", by a
transceiver either
directly or by using a
short drop cable.
Where
Home
Small Office
Office
Internet Cafe
When
When it is
centralized star
topology can be
used.
When it is
decentralized bus
topology can be
used.
Why
It suits the
environment
It suits the
environment
Ring
In a ring topology
network computers
are connected by a
single loop of cable,
the data signals travel
around the loop in
one direction, passing
through each
computer
Computer lab
Library
When it is
centralized ring
topology can be
used
It suits the
environment

5. Server
What is server?
A server is a system (software and suitable computer hardware) that
responds to requests across a computer network to provide, or help
to provide, a network. Servers can be run on a dedicated computer,
which is also often referred to as "the server", but many networked
computers are capable of hosting servers. In many cases, a computer can provide several
services and have several servers running.
Features of server
Servers operate within a client-server architecture, servers are computer programs running to
serve the requests of other programs, the clients. Thus, the server performs some task on
behalf of clients. The clients typically connect to the server through the network but may run on
the same computer. In the context of Internet Protocol (IP) networking, a server is a program
that operates as a socket listener.
Servers often provide essential services across a network, either to private users inside a large
organization or to public users via the Internet. Typical computing servers are database
server, file server, mail server, print server, web server, gaming server, application server, or
some other kind of server.
Numerous systems use this client / server networking model including Web sites and email
services. An alternative model, peer-to-peer networking enables all computers to act as either a
server or client as needed.
Products of server

6. Comparison of server
Compare and contrast the two server systems.
Currently, OME offers two different version of its server software: the original
Perl-based OME server which has been in development since 2000; and a
lighter, Java-based server/client suite known as the OMERO Platform which
provides a hi-performance data management and visualization solution.
The two servers have different strength and weaknesses due to the underlying
architecture they use. They can also each be used in different ways. There is
however a recommended use for each and it is these we will compare in depth.
Client
What is client?
A client is a computer program that, as part of its operation, relies on sending a request to
another computer program (which may or may not be located on another computer). For
example, web browsers are clients that connect to web servers and retrieve web pages for
display. Email clients retrieve email from mail servers. Online chat uses a variety of clients,
which vary depending on the chat protocol being used. Multiplayer video games or online
video games may run as a client on each computer. The term "client" may also be applied
to computers or devices that run the client software or users that use the client software.
Product of client

7. Comparison of clients
Based on the results of this study, it is clear that thin-client devices are more energyefficient than personal computers, with some models using 85 percent less power than
their PC rivals in real world environments. This energy efficiency translates into
significant, measurable cost savings for businesses both in the short term and the
long term, whether an organization is using dozens, hundreds or thousands of desktop
devices. Finally, the ability
to deploy desktop devices with integrated liquid crystal displays (LCDs) affords
businesses an even greater opportunity to reduce the energy consumption of their IT
environment.
Features of client
A client is part of a client–server model, which is still used today. Clients and servers
may be computer programs run on the same machine and connect via inter-process
communication techniques. Combined with Internet sockets, programs may connect
to a service operating on a possibly remote system through the Internet protocol
suite. Servers wait for potential clients to initiate connections that they may accept.
The term was first applied to devices that were not capable of running their own
stand-alone programs, but could interact with remote computers via a network.
These dumb terminals were clients of the time-sharing mainframe computer.

8. Internet Devices
Switch
A network switch or switching hub is a computer networking device that links network
segments or network devices. The term commonly refers to a multi-port network bridge that
processes and routes data at the data link layer (layer 2) of the OSI model. Switches that
additionally process data at the network layer (layer 3) and above are often called layer-3
switches or multilayer switches.
Switches exist for various types of networks including Fibre Channel, Asynchronous
Transfer Mode, Infini Band, Ethernet and others. The first Ethernet switch was introduced
by Kalpana in 1990.
Bridge
Bridges operate at the data link layer (Layer 2) of the OSI model. Bridges inspect incoming
traffic and decide whether to forward or discard it. An Ethernet bridge, for example, inspects
each incoming Ethernet frame - including the source and destination MAC addresses, and
sometimes the frame size - in making individual forwarding decisions.

9. Bridges serve a similar function as switches, that also operate at Layer 2. Traditional bridges,
though, support one network boundary, whereas switches usually offer four or more hardware
ports. Switches are sometimes called "multi-port bridges" for this reason.
Repeater
Network repeaters regenerate incoming electrical, wireless or optical signals.
With physical media like Ethernet or Wi-Fi, data transmissions can only span a
limited distance before the quality of the signal degrades. Repeaters attempt to
preserve signal integrity and extend the distance over which data can safely
travel.
Router
A router is a device that forwards data packets between computer networks, creating an
overlay internetwork. A router is connected to two or more data lines from different networks.
When a data packet comes in one of the lines, the router reads the address information in the
packet to determine its ultimate destination. Then, using information in its routing
table or routing policy, it directs the packet to the next network on its journey. Routers perform
the "traffic directing" functions on the Internet. A data packet is typically forwarded from one
router to another through the networks that constitute the internetwork until it reaches its
destination node
What is Internet devices?
To access the internet, you not only need an internet connection, but you
also need a device to access the internet on.
The range of devices to connect to the internet on is increasing all the
time.

10. We used to access the internet on desktop or laptop computers. Now,
you might carry a smartphone or a tablet, or even use the internet on a
smart TV
Feature
Whichever device you use when you’re banking, shopping, surfing or social
networking online, the Internet holds the same security risks – including malware
infections, cybercrime and phishing. So it’s important to ensure all your
connected devices, and the personal data you store on them, are protected
against all the threats the Web can deliver.
Internet Security – Multi-Device is the easy-to-use, one-license, multi-platform
security solution that protects virtually any combination of PCs, Macs, Android
smart phones and Android tablets to give you:
Comparison
Although Wi-Fi and 3G can be considered complementary technologies,
sometimes you have to choose one over the other for either budget reasons
(mobile Internet data plans, especially for multiple devices, can be costly) or
technological limitations (when the Apple iPad first came out, for example, users
had to choose between getting a Wi-Fi-only model or wait for the version that
offered 3G as well as Wi-Fi).
Product

11. Media
What is a media?
Almost all Media Converters that are commonly available on the market claim to
have a feature called Link-Pass Through. However, in most products, this feature is
poorly implemented and does not work properly. If you choose a low-end Media
Converter, the end to end connection on your network will always appear as if it is
up and running, even though the fiber connection may be broken or disconnected.
The end devices, such as switches, continue to see the connection as healthy and
never report a problem to an enterprise network management system. Your network
will be down and you won’t know why or what to fix!
Product
The VanCryst™ Media Matrix Solution is a combination of the VM0808T 8x8 Cat 5 A/V Matrix
Switch and the VE500 / VE300 A/V Over Cat 5 Extender. The VM0808T is a Matrix Switch that
routes and distributes audio, video, and RS-232 signals over distances of up to 300 m with
1280x1024 video resolution.

12. Comparison
While we shouldn’t make light of 4 million homes without power in the aftermath of
Irene, it was much less of a storm than advertised. I’ve seen worse damage—and
had longer power interruptions (my power went out last night at 3 am for a grand
total of two minutes)—from normal severe summer thunderstorms. However, a
week ago it was by no means clear that the storm would weaken as it did, and the
reverse might well have occurred.
Features
Data hub shall deliver media and data service to up to six
different locations. Data hub shall offer Category 5e
performance to support applications that require additional
bandwidth. Data hub shall offer 110 punch down terminations
for high-performance capability. Punch downs shall also be
positioned on front of hub for easy access to terminations
within the enclosure. Data hub shall also offer quick

13. installation features for easy moves, adds, and changes
Nos
What is NOS
Network Operating System refers to software that implements an operating
system of some kind that is oriented to computer networking. For example, one that
runs on a server and enables the server to manage data, users, groups, security,
applications, and other networking functions.[1] The network operating system is
designed to allow shared file and printer access among multiple computers in a
network, typically a local area network (LAN), a private network or to other networks.
Product of nos

14. Features of nos
Windows
Directory Services
A directory service is a database of user accounts and other information that
network administrators use to control access to shared network resources. When
users connect to a network, they have to be authenticated before they can access
network resources. Authentication is the process of checking the user's credentials
(usually a user name and a password) against the directory. Users that supply the
proper credentials are permitted access according to the permissions specified by
the network administrator.
Client Support
Windows 3.x, Windows 95, Windows 98, and Windows NT Workstation 4.0 Windows
2000 Professional, Xp Pro. Vista Ultimate, Vista Business.
Interoperability
Windows 2000,2003,2008 Server supports UNIX, Novell NetWare, Windows NT
Server 4.0, and Macintosh.
Authentication
Successful user authentication in a Windows 2000,2003,2008 computing
environment consists of separate processes: interactive logon, which confirms the
user's identification to either a domain account or a local computer, and network
authentication, which confirms the user's identification to any network service that
the user attempts to access.

15. Types of authentication
Kerberos V5 is used with either a password or a smart card for interactive logon. It is
also the default method of network authentication for services.The Kerberos V5
protocol verifies both the identity of the user and network services Secure Socket
Layer/Transport Layer Security (SSL/TLS) authentication, is used when a user
attempts to access a secure Web server.
Comparison of nos
A network operating system (NOS) is a computer operating system system
that is designed primarily to support workstation, personal computer,
and, in some instances, older terminalthat are connected on a local area
network (LAN). Artisoft's LANtastic, Banyan VINES, Novell's NetWare, and
Microsoft's LAN Manager are examples of network operating systems. In
addition, some multi-purpose operating systems, such as Windows
NT and Digital's OpenVMS come with capabilities that enable them to be
described as a network operating system.
A network operating system provides printer sharing, common file system
and database sharing, application sharing, and the ability to manage a
network name directory, security, and other housekeeping aspects of a
network.