a.
Computer
The best computer for you is ultimately based on several variables including budget, usage, and
your field of study. Systems less than these suggested specifications will work on the network.
Main System Components
Intel Core i5 processor or better
4GB RAM or more
1TB hard drive space for desktop computers; solid-state hard drive for laptops
Windows OS: 8 or newer
Mac OS: 10.7 (Lion) or newer
802.11 N wireless card or above (5GHz or faster recommended)
100mbps network card or faster, with RJ-45 cable (optional, for wired connections)
o Service & Support
You should purchase a support and/or damage plan for your equipment. We recommend a three
or four year agreement for the best coverage. Due to liabilities and warranty restrictions, IT staff
members are not permitted to perform hardware repair work on personally-owned equipment.
o Anti-Virus Software
Up to date anti-virus software should be installed on your personal computer, configured to
automatically update, and scheduled to run regular scans. You are welcome to install either a free
or subscription-based anti-virus suite.
NOTE: You should not run multiple anti-virus programs concurrently on the same machine.
It is a good idea to have anti-malware / anti-spyware software, or use a security suite which
provides both anti-virus and anti-malware in one software package. Enable your computers
firewall for additional protection.
o Peripherals & Accessories
When deciding on peripheral devices such as printers, speakers, docks, external hard drives, etc,
take your residence hall desk space into account.
Personal printers should plug directly into your computer via USB connection. Wireless printing
is not permitted due to interference with the campus wifi network.
o Productivity Software
Microsoft Office 2013 Professional is available on all public computer lab workstations. Office
365 is available free of charge to all students, faculty, and staff on up to five computers and up to
five tablets. If you choose to purchase Office for your personal computer it should be version
2010 or newer for Windows; for Macs, 2011 or newer.
Additionally, all students are provided with a lifelong Gmail@Valpo account which includes the
full suite of Google Apps and Google Drive functionality.
Processor - This is the speed of your CPU. Virtually all processors will be Intel or AMD.
If you are unsure what the processor model means, do a web search to see the details.
Memory (RAM) This is the amount of memory you have on your computer. If you
have a 32-bit operating system, you can only use up to 4 GB of RAM, even if you have
more installed.
System type This will tell you what version of Windows you are running. Newer
versions of Windows will also tell you if you have a 32-bit (x86) or 64-bit (x64)
processor.
b. LAN card, cable, rj45 etc.
The LAN (Local Area Network) card is a 'door' to the network from a computer. Any type of
network activity requires a LAN card: the Internet, network printer, connecting computers
together, and so on. Today many devices contain a network card, including televisions for their
Internet apps, Blu-ray players, mobile phones, VoIP, desk phones, and even refrigerators. LAN
cards are hardware devices that can be added to a computer, or they can be integrated into the
main hardware of the computer.
What does a LAN card look like? Some LAN cards look like credit cards.
Some cards, such as a PCMCIA card, can be used in a laptop. There are many other ways of
connecting the LAN card to a computer. Some cards are connected via the USB port, some via
the PCI port inside of the computer, and some are even embedded inside of the computer. Most
laptops today have integrated LAN cards both for wired and wireless networking.
A PCI card goes inside of a PC computer. The card shows an Ethernet port, which is the spot
where you plug in a network cable. The LAN card you select often determines the protocols that
are used on the network. For example, an Ethernet card will allow communication via the
Ethernet protocol. A coax card would allow for a bus topology network and a new set of
protocols. A fiber cable would have a different cable plugin, and it would likely work with Wide
Area Network protocols. The Ethernet port on a LAN card looks like a phone jack, but it is
wider and has more pins.
A typical Ethernet cable, or network cable, is the plugin that goes into the LAN card, or the
Network Interface Controller (NIC).
The purpose of a LAN card is to create a physical connection to the network - to provide an open
'door,' as it were. The first interface supported by a LAN card is a physical interface through
which the cable plugs into the card. The interface is well-defined in technical documentation,
which is why standard network cables fit most standard LAN cards. The second function of a
LAN card is to provide a data link. There is a theoretical model in computer networking
called OSI (Open Systems Interconnection). This model, or way of explaining networks,
includes seven layers. The first two layers are the physical layer and the data link. Each layer of
the OSI model allows for other layers to be independent. Upgrading or changing one layer does
not affect the others. This means that if plugins change for all LAN cards, other elements, like
the protocols, don't have to change.
A characteristic of cable that must not be overlooked is its fire rating. Cable installed in the
plenum space, which is the airspace between the ceiling and the next floor or roof, must be
installed in metal conduit, or must meet local fire codes. In the event of a fire, the cable must not
produce noxious or hazardous gases that would be pumped to other parts of a structure through
the plenum. Nonplenum cables have PVC (polyvinyl chloride) jackets whileplenum-rated
cables have jackets made with fluoropolymers such as Du Pont's Teflon.
Straight cable This is the simplest type of cable. It consists of copper wires surrounded
by an insulator. The wire comes in bundles or as flat "ribbon" cables and is used to
connect various peripheral devices over short distances. Cables for internal disk drives
are typically flat cables with multiple transmission wires running in parallel.
Twisted-pair cable This cable consists of copper-core wires surrounded by an
insulator. Two wires are twisted together to form a pair, and the pair forms a balanced
circuit (voltages in each pair have the same amplitude but are opposite in phase). The
twisting protects against EMI (electromagnetic interference) and RFI (radio frequency
interference). A typical cable has multiple twisted pairs, each color-coded to differentiate
it from other pairs. UTP (unshielded twisted-pair) has been used in the telephone network
and is commonly used for data networking in the United States. STP (shielded twisted-
pair) cable has a foil shield around the wire pairs in a cable to provide superior immunity
to RFI. Traditional twisted-pair LANs use two pairs, one for transmit and one for receive,
but newer Gigabit Ethernet networks use four pairs to transmit and receive
simultaneously. UTP and STP are constructed of 100-ohm, 24-AWG solid conductors.
Coaxial cable This cable consists of a solid copper core surrounded by an insulator, a
combination shield and ground wire, and an outer protective jacket. In the early days of
LANs, coaxial cable was used for its high bit rates. An Ethernet Thinnet (10Base-2)
network has a data rate of 10Mbits/sec and implements a bus topology in which each
station is attached to a single strand of cable. Today, hierarchical wiring schemes are
considered more practical, and even though more twisted pair wire is required to cable
such a network, cost has dropped, making such networks very practical.
Fiber-optic cable This cable consists of a center glass core through which light waves
propagate. This core is surrounded by a glass cladding that basically reflects the inner
light of the core back into the core. A thick plastic outer jacket surrounds this assembly,
along with special fibers to add strength. Fiber-optic cable is available with a metal core
for strength if the cable will be hung over distances.
Copper Cable Characteristics
Information is transmitted over copper cable by applying variable or discrete voltages at one end
of the cable and reading those voltages at the other end. Data signals are discrete pulses of
electricity (or light in the case of fiber cable). As mentioned, this discussion is oriented toward
twisted-pair cable. Some of the characteristics discussed here only apply to wires that are
twisted.
The following relationship exists between the frequency of the electrical signal and the rate at
which data is transmitted:
Bandwidth The bandwidth of a communication system is the highest frequency range
that it uses. This is defined by the engineering specification of the particular network.
Some examples are listed in Table 1.
Data rate The actual data throughput of a cable, after applying encoding and
compression schemes to more efficiently use the bandwidth of the cable.
RJ45 is a type of connector commonly used for Ethernet networking. It looks similar to a
telephone jack, but is slightly wider. Since Ethernet cables have an RJ45 connector on each end,
Ethernet cables are sometimes also called RJ45 cables.
The "RJ" in RJ45 stands for "registered jack," since it is a standardized networking interface. The
"45" simply refers to the number of the interface standard. Each RJ45 connector has eight pins,
which means an RJ45 cable contains eight separate wires. If you look closely at the end of an
Ethernet cable, you can actually see the eight wires, which are each a different color. Four of
them are solid colours, while the other four are striped.
RJ45 cables can be wired in two different ways. One version is called T-568A and the other is T-
568B. These wiring standards are listed below:
T-568A T-568B
1. White/Green (Receive +) 1. White/Orange (Transmit +)
2. Green (Receive -) 2. Orange (Transmit -)
3. White/Orange (Transmit +) 3. White/Green (Receive +)
4. Blue 4. Blue
5. White/Blue 5. White/Blue
6. Orange (Transmit -) 6. Green (Receive -)
7. White/Brown 7. White/Brown
8. Brown 8. Brown
The T-568B wiring scheme is by far the most common, though many devices support the T-
568A wiring scheme as well. Some networking applications require a crossover Ethernet cable,
which has a T-568A connector on one end and a T-568B connector on the other. This type of
cable is typically used for direct computer-to-computer connections when there is no router, hub,
or switch available.
The RJ-45 is often confused with the 8P8C standard which looks almost identical but has
particular properties regarding signal loss as the cabling is always made up of twisted pairs, a
noise cancelling technology. The most common confusion is where RJ-45 is thought to be the
same as an Ethernet connector, which is actually an RJ45S (or 8P8C) connection. RJ-45 is a
telephony specification and although the connectors are almost identical to 8P8C, they have
different signal conduction characteristics.
The 8P8C standard connectors are commonly referred to as RJ-45S.
c. Network (types, kinds, advantages, disadvantage etc.)
ADVANTAGES OF NETWORKING:
1. Easy Communication and Speed
It is very easy to communicate through a network. People can communicate efficiently using a
network with a group of people. They can enjoy the benefit of emails, instant messaging,
telephony, video conferencing, chat rooms, etc.
2. Ability to Share Files, Data and Information
This is one of the major advantages of networking computers. People can find and share
information and data because of networking. This is beneficial for large organizations to
maintain their data in an organized manner and facilitate access for desired people.
3. Sharing Hardware
Another important advantage of networking is the ability to share hardware. For an example, a
printer can be shared among the users in a network so that theres no need to have individual
printers for each and every computer in the company. This will significantly reduce the cost of
purchasing hardware.
4. Sharing Software
Users can share software within the network easily. Networkable versions of software are
available at considerable savings compared to individually licensed version of the same software.
Therefore large companies can reduce the cost of buying software by networking their
computers.
5. Security
Sensitive files and programs on a network can be password protected. Then those files can only
be accessed by the authorized users. This is another important advantage of networking when
there are concerns about security issues. Also each and every user has their own set of privileges
to prevent them accessing restricted files and programs.
6. Speed
Sharing and transferring files within networks is very rapid, depending on the type of network.
This will save time while maintaining the integrity of files.
DISADVATAGES OF NETWORKING:
1. Breakdowns and Possible Loss of Resources
One major disadvantage of networking is the breakdown of the whole network due to an issue of
the server. Such breakdowns are frequent in networks causing losses of thousands of dollars each
year. Therefore once established it is vital to maintain it properly to prevent such disastrous
breakdowns. The worst scenario is such breakdowns may lead to loss of important data of the
server.
2. Expensive to Build
Building a network is a serious business in many occasions, especially for large scale
organizations. Cables and other hardware are very pricey to buy and replace.
3. Security Threats
Security threats are always problems with large networks. There are hackers who are trying to
steal valuable data of large companies for their own benefit. So it is necessary to take utmost care
to facilitate the required security measures.
4. Bandwidth Issues
In a network there are users who consume a lot more bandwidth than others. Because of this
some other people may experience difficulties.
Although there are disadvantages to networking, it is a vital need in todays environment. People
need to access the Internet, communicate and share information and they cant live without that.
Therefore engineers need to find alternatives and improved technologies to overcome issues
associated with networking. Therefore we can say that computer networking is always beneficial
to have even if there are some drawbacks.
A network topology refers to the way in which nodes in a network are connected to one another.
The network structure defines how they communicate. They describe the physical and logical
arrangement of network nodes. Each kind of arrangement of the network nodes has its own
advantages and disadvantages.
Types of Networks
1. Local Area Networks
Local area networks (LANs) are used to connect networking devices that are in a very close
geographic area, such as a floor of a building, a building itself, or a campus environment.
2. Wide Area Networks
Wide area networks (WANs) are used to connect LANs together. Typically, WANs are used
when the LANs that must be connected are separated by a large distance.
3. Metropolitan Area Networks
A metropolitan area network (MAN) is a hybrid between a LAN and a WAN.
4. Storage Area Networks
Storage area networks (SANs) provide a high-speed infrastructure to move data between storage
devices and file servers.
5. Content Networks
Content networks (CNs) were developed to ease users' access to Internet resources.
Companies deploy basically two types of CNs:
caching downloaded Internet information
Distributing Internet traffic loads across multiple servers
6. Intranet
An intranet is basically a network that is local to a company. In other words, users from within
this company can find all of their resources without having to go outside of the company. An
intranet can include LANs, private WANs and MANs,
7. Extranet
An extranet is an extended intranet, where certain internal services are made available to known
external users or external business partners at remote locations.
8. Internet
An internet is used when unknown external users need to access internal resources in your
network. In other words, your company might have a web site that sells various products, and
you want any external user to be able to access this service.
9. VPN
A virtual private network (VPN) is a special type of secured network. A VPN is used to provide
a secure connection across a public network, such as an internet. Extranets typically use a VPN
to provide a secure connection between a company and its known external users or offices.
Authentication is provided to validate the identities of the two peers.
Confidentiality provides encryption of the data to keep it private from prying eyes.
Integrity is used to ensure that the data sent between the two devices or sites has not been
tampered with.
Different Kinds Of Network Topology In Computer Networks
o Bus topologies
All the devices on a bus topology are connected by one single cable. When one computer sends
a signal up the wire, all the computers on the network receive the information, but only one
accepts the information. The rest regrets the message. One computer can send a message at a
time. A computer must wait until the bus is free before it can transmit. When the signal reaches
the end of the wire, it bounces back and travels back up the wire. When a signal echoes back and
forth along an unterminated bus, it is called ringing. To stop the signals from ringing, attach
terminators at either end of the segment. The terminators absorb the electrical energy and stop
the reflection.
o Star Topology
All the cables run from the computers to a central location, where they are all connected by a
device called a hub. Each computer on a star network communicates with a central hub that
resends the message either to all the computers or only to the destination computers. Hub can be
active or passive in the star network Active hub regenerates the electrical signal and sends it to
all the computers connected to it. Passive hub does not amplify or regenerate signal and does not
require electrical power to run. We can expand a star network by placing another star hub.
o Ring Topology
Each computer is connected to the next computer ,with the last one connected to the first. Every
computer is connected to the next computer in the ring, and each retransmits what it receives
from the previous computer. The message flow around the ring in one direction. Some ring
networks do token passing. It passes around the ring until a computer wishes to send information
to another computer. The computer adds an electronic address and data and sends it around the
ring. Each computer in sequence receives the token and the information and passes them to the
next until either the electronic address matches the address of the computer or the token returns
to the origin. The receiving computer returns a message to the originator indicating that the
message has been received. The sending computer then creates another token and place it on the
network, allowing another station to capture the token and being transmitted.
o Mesh Topology
The mesh topology connects all devices (nodes) to each other for redundancy and fault
tolerance. It is used in WANs to interconnect LANs and for mission critical networks like those
used by banks and financial institutions. Implementing the mesh topology is expensive and
difficult.
http://www.valpo.edu/it/help/computer-specifications/
http://www.wikihow.com/Check-Computer-Specifications
http://study.com/academy/lesson/lan-card-definition-function-types.html
http://www.linktionary.com/c/cabling.html
http://techterms.com/definition/rj45
https://www.techopedia.com/definition/25742/registered-jack-45-rj45
http://study.com/academy/lesson/lan-card-definition-function-types.html
http://www.brighthub.com/computing/hardware/articles/65406.aspx
http://ecestudyaid.blogspot.com/2012/07/different-kids-of-network-topology-in.html
