Friday, 7 March 2014

The Disadvantages of Networking

The Disadvantages  of Networking


Here are a few of the items that balance against the advantages of networking.
  • Network Hardware, Software and Setup Costs: Computers don't just magically network themselves, of course. Setting up a network requires an investment in hardware and software, as well as funds for planning, designing and implementing the network. For a home with a small network of two or three PCs, this is relatively inexpensive, possibly amounting to less than a hundred dollars with today's low prices for network hardware, and operating systems already designed for networks. For a large company, cost can easily run into tens of thousands of dollars—or more. 
  • Hardware and Software Management and Administration Costs: In all but the smallest of implementations, ongoing maintenance and management of the network requires the care and attention of an IT professional. In a smaller organization that already has a system administrator, a network may fall within this person's job responsibilities, but it will take time away from other tasks. In more substantial organizations, a network administrator may need to be hired, and in large companies an entire department may be necessary. 
  • Undesirable Sharing: With the good comes the bad; while networking allows the easy sharing of useful information, it also allows the sharing of undesirable data. One significant “sharing problem” in this regard has to do with viruses, which are easily spread over networks and the Internet. Mitigating these effects costs more time, money and administrative effort. 
  • Illegal or Undesirable Behavior: Similar to the point above, networking facilitates useful connectivity and communication, but also brings difficulties with it. Typical problems include abuse of company resources, distractions that reduce productivity, downloading of illegal or illicit materials, and even software piracy. In larger organizations, these issues must be managed through explicit policies and monitoring, which again, further increases management costs. 
  • Data Security Concerns: If a network is implemented properly, it is possible to greatly improve the security of important data. In contrast, a poorly-secured network puts critical data at risk, exposing it to the potential problems associated with hackers, unauthorized access and even sabotage.


The Advantages of Computer Networking

The Advantages of  Computer Networking
You have undoubtedly heard the “the whole is greater than the sum of its parts”. This phrase describes networking very well, and explains why it has become so popular. A network isn't just a bunch of computers with wires running between them. Properly implemented, a network is a system that provides its users with unique capabilities, above and beyond what the individual machines and their software applications can provide.
Most of the benefits of networking can be divided into two generic categories: connectivity and sharing. Networks allow computers, and hence their users, to be connected together. They also allow for the easy sharing of information and resources, and cooperation between the devices in other ways. Since modern business depends so much on the intelligent flow and management of information, this tells you a lot about why networking is so valuable.
Here, in no particular order, are some of the specific advantages generally associated with networking:
  • Connectivity and Communication: Networks connect computers and the users of those computers. Individuals within a building or work group can be connected into local area networks (LANs); LANs in distant locations can be interconnected into larger wide area networks (WANs). Once connected, it is possible for network users to communicate with each other using technologies such as electronic mail. This makes the transmission of business (or non-business) information easier, more efficient and less expensive than it would be without the network. 
  • Data Sharing: One of the most important uses of networking is to allow the sharing of data. Before networking was common, an accounting employee who wanted to prepare a report for her manager would have to produce it on his PC, put it on a floppy disk, and then walk it over to the manager, who would transfer the data to her PC's hard disk. (This sort of “shoe-based network” was sometimes sarcastically called a “sneakernet”.)

    True networking allows thousands of employees to share data much more easily and quickly than this. More so, it makes possible applications that rely on the ability of many people to access and share the same data, such as databases, group software development, and much more.
     Intranets and extranets can be used to distribute corporate information between sites and to business partners. 
  • Hardware Sharing: Networks facilitate the sharing of hardware devices. For example, instead of giving each of 10 employees in a department an expensive color printer (or resorting to the “sneakernet” again), one printer can be placed on the network for everyone to share. 
  • Internet Access: The Internet is itself an enormous network, so whenever you access the Internet, you are using a network. The significance of the Internet on modern society is hard to exaggerate, especially for those of us in technical fields. 
  • Internet Access Sharing: Small computer networks allow multiple users to share a single Internet connection. Special hardware devices allow the bandwidth of the connection to be easily allocated to various individuals as they need it, and permit an organization to purchase one high-speed connection instead of many slower ones. 
  • Data Security and Management: In a business environment, a network allows the administrators to much better manage the company's critical data. Instead of having this data spread over dozens or even hundreds of small computers in a haphazard fashion as their users create it, data can be centralized on shared servers. This makes it easy for everyone to find the data, makes it possible for the administrators to ensure that the data is regularly backed up, and also allows for the implementation of security measures to control who can read or change various pieces of critical information. 
  • Performance Enhancement and Balancing: Under some circumstances, a network can be used to enhance the overall performance of some applications by distributing the computation tasks to various computers on the network. 
  • Entertainment: Networks facilitate many types of games and entertainment. The Internet itself offers many sources of entertainment, of course. In addition, many multi-player games exist that operate over a local area network. Many home networks are set up for this reason, and gaming across wide area networks (including the Internet) has also become quite popular. Of course, if you are running a business and have easily-amused employees, you might insist that this is really a disadvantage of networking and not an advantage!


Introduction to TCP/IP Networks:

Introduction to TCP/IP Networks:
TCP/IP-based networks play an increasingly important role in computer networks. Perhaps one reason for their
appeal is that they are based on an open specification that is not controlled by any vendor.
What Is TCP/IP?
TCP stands for Transmission Control Protocol and IP stands for Internet Protocol. The term TCP/IP is not limited just
to these two protocols, however. Frequently, the term TCP/IP is used to refer to a group of protocols related to the
TCP and IP protocols such as the User Datagram Protocol (UDP), File Transfer Protocol (FTP), Terminal Emulation
Protocol (TELNET), and so on.
The Origins of TCP/IP
In the late 1960s, DARPA (the Defense Advanced Research Project Agency), in the United States, noticed that there
was a rapid proliferation of computers in military communications. Computers, because they can be easily
programmed, provide flexibility in achieving network functions that is not available with other types of communications
equipment. The computers then used in military communications were manufactured by different vendors and were
designed to interoperate with computers from that vendor only. Vendors used proprietary protocols in their
communications equipment. The military had a multi vendor network but no common protocol to support the
heterogeneous equipment from different vendors
Net work Cables and Stuff:
In the network you will commonly find three types of cables used these are the, coaxial cable, fiber optic and twisted
pair.
Thick Coaxial Cable
This type cable is usually yellow in color and used in what is called thicknets, and has two conductors. This coax can
be used in 500-meter lengths. The cable itself is made up of a solid center wire with a braided metal shield and
plastic sheathing protecting the rest of the wire.
Thin Coaxial Cable
Basic Networking Tutorial

As with the thick coaxial cable is used in thicknets the thin version is used in thinnets. This type cable is also used
called or referred to as RG-58. The cable is really just a cheaper version of the thick cable.
Fiber Optic Cable
As we all know fiber optics are pretty darn cool and not cheap. This cable is smaller and can carry a vast amount of
information fast and over long distances.
Twisted Pair Cables
These come in two flavors of unshielded and shielded.
Shielded Twisted Pair (STP)

Is more common in high-speed networks. The
biggest difference you will see in the UTP and
STP is that the STP use's metallic shield
wrapping to protect the wire from interference.
-Something else to note about these cables is
that they are defined in numbers also. The bigger
the number the better the protection from
interference. Most networks should go with no
less than a CAT 3 and CAT 5 is most
recommended.
-Now you know about cables we need to know
about connectors. This is pretty important and
you will most likely need the RJ-45 connector.
This is the cousin of the phone jack connector
and looks real similar with the exception that the
RJ-45 is bigger. Most commonly your connector
are in two flavors and this is BNC (Bayonet Naur Connector) used in thicknets and the RJ-45 used in smaller
networks using UTP/STP.
Unshielded Twisted Pair (UTP)
This is the most popular form of cables in the network and the cheapest form that you can go with. The UTP has four
pairs of wires and all inside plastic sheathing. The biggest reason that we call it Twisted Pair is to protect the wires
from interference from themselves. Each wire is only protected with a thin plastic sheath.
Ethernet Cabling
Basic Networking Tutorial

Now to familiarize you with more on the Ethernet and it's cabling we need to look at the 10's. 10Base2, is considered
the thin Ethernet, thinnet, and thinwire which uses light coaxial cable to create a 10 Mbps network. The cable
segments in this network can't be over 185 meters in length. These cables connect with the BNC connector. Also as
a note these unused connection must have a terminator, which will be a 50-ohm terminator.
10Base5, this is considered a thicknet and is used with coaxial cable arrangement such as the BNC connector. The
good side to the coaxial cable is the high-speed transfer and cable segments can be up to 500 meters between
nodes/workstations. You will typically see the same speed as the 10Base2 but larger cable lengths for more
versatility.
10BaseT, the “T” stands for twisted as in UTP (Unshielded Twisted Pair) and uses this for 10Mbps of transfer. The
down side to this is you can only have cable lengths of 100 meters between nodes/workstations. The good side to
this network is they are easy to set up and cheap! This is why they are so common an ideal for small offices or
homes.
100BaseT, is considered Fast Ethernet uses STP (Shielded Twisted Pair) reaching data transfer of 100Mbps. This
system is a little more expensive but still remains popular as the 10BaseT and cheaper than most other type
networks. This on of course would be the cheap fast version.
10BaseF, this little guy has the advantage of fiber optics and the F stands for just that. This arrangement is a little
more complicated and uses special connectors and NIC's along with hubs to create its network. Pretty darn neat and
not to cheap on the wallet.
An important part of designing and installing an Ethernet is selecting the appropriate Ethernet medium. There are four
major types of media in use today: Thickwire for 10BASE5 networks, thin coax for 10BASE2 networks, unshielded
twisted pair (UTP) for 10BASE-T networks and fiber optic for 10BASE-FL or Fiber-Optic Inter-Repeater Link (FOIRL)
networks. This wide variety of media reflects the evolution of Ethernet and also points to the technology's flexibility.

Thickwire was one of the first cabling systems used in Ethernet but was expensive and difficult to use. This evolved tthin coax, which is easier to work with and less expensive.

Basic Networking Knowledge

Computer Networking:
What is a computer Network?
A network is any collection of independent computers that communicate with one another over a shared network
medium. A computer network is a collection of two or more connected computers. When these computers are joined
in a network, people can share files and peripherals such as modems, printers, tape backup drives, or CD-ROM
drives. When networks at multiple locations are connected using services available from phone companies, people
can send e-mail, share links to the global Internet, or conduct video conferences in real time with other remote users.
When a network becomes open sourced it can be managed properly with online collaboration software. As
companies rely on applications like electronic mail and database management for core business operations,
computer networking becomes increasingly more important.
Every network includes:
At least two computers Server or Client workstation.
Networking Interface Card's (NIC)
A connection medium, usually a wire or cable, although wireless communication between
networked computers and peripherals is also possible.
Network Operating system software, such as Microsoft Windows NT or 2000, Novell NetWare, Unix
and Linux.                          
Types of Networks:
LANs (Local Area Networks)
A network is any collection of independent computers that communicate with one another over a shared network
medium. LANs are networks usually confined to a geographic area, such as a single building or a college campus.
LANs can be small, linking as few as three computers, but often link hundreds of computers used by thousands of
people. The development of standard networking protocols and media has resulted in worldwide proliferation of LANs
throughout business and educational organizations.
WANs (Wide Area Networks)
Wide area networking combines multiple LANs that are geographically separate. This is accomplished by connecting
the different LANs using services such as dedicated leased phone lines, dial-up phone lines (both synchronous and
asynchronous), satellite links, and data packet carrier services. Wide area networking can be as simple as a modem
and remote access server for employees to dial into, or it can be as complex as hundreds of branch offices globally
linked using special routing protocols and filters to minimize the expense of sending data sent over vast distances.
Internet
The Internet is a system of linked networks that are worldwide in scope and facilitate data communication services
such as remote login, file transfer, electronic mail, the World Wide Web and newsgroups.
Basic Networking Tutorial
With the meteoric rise in demand for connectivity, the Internet has become a communications highway for millions of
users. The Internet was initially restricted to military and academic institutions, but now it is a full-fledged conduit for
any and all forms of information and commerce. Internet websites now provide personal, educational, political and
economic resources to every corner of the planet.
Intranet
With the advancements made in browser-based software for the Internet, many private organizations are
implementing intranets. An intranet is a private network utilizing Internet-type tools, but available only within that
organization. For large organizations, an intranet provides an easy access mode to corporate information for
employees.
MANs (Metropolitan area Networks)
The refers to a network of computers with in a City.
VPN (Virtual Private Network)
VPN uses a technique known as tunneling to transfer data securely on the Internet to a remote access server on your
workplace network. Using a VPN helps you save money by using the public
Internet instead of making long–distance phone calls to connect securely
with your private network. There are two ways to create a VPN connection,
by dialing an Internet service provider (ISP), or connecting directly to
Internet.
Categories of Network:
Network can be divided in to two main
categories:
Peer-to-peer.
Server – based.
In peer-to-peer networking there are no dedicated servers or hierarchy




among the computers. All of the computers are equal and therefore known
as peers. Normally each computer serves as Client/Server and there is no
one assigned to be an administrator responsible for the entire network.
Peer-to-peer networks are good choices for needs of small organizations
where the users are allocated in the same general area, security is not an
issue and the organization and the network will have limited growth within

the foreseeable future