Home and small office networking
has in the past two or three years become as common place as apple pie.
Well, maybe, not as common as apple pie, but, it is really main stream
for all of us now. Just what are we talking about when we talk about networks.
A network, or LAN (Local
a reality when two or more computers, known as hosts or nodes, are connected
together in some fashion. Connecting computers together greatly extends
the communication that can be accomplished between the users who are talking
to one another. Ever since the PC was created, it has been used as a communication
tool. Coupling two or more computers together just enhances that communication
Coupling those two or more computers together requires several pieces
of hardware and software that are not commonly part of the basic PC. First,
the hardware components include at a minimum, cabling, NIC (Network
Cards), and possibly
hubs. Second, the OS (Operating
must have utilities that recognize other computers, to make the OS “network
ready”. This overview will attempt to cover the how and what of networks.
I have been writing about SOHO (Small
networks since 1997 in my Comm
Corner column. In these Comm Corner articles about SOHO, I defined
it as a network when two or more computers were connected together. There
is no real difference between two or more computers connected together
at home or in an office.
Communication by most of us in the beginning, 1980's or so, was via
word of mouth, passing a floppy disk to one another or using our analog
modem to connect to the local BBS (Bulletin
Service) or another
computer user at 300 baud on the POTS (Plain
The Microsoft DOS OS was not network ready without real black magic additions
make it recognize the network hardware and software. Other OS systems,
were, at this time, capable of networking or providing the means of connecting
the computers together. UNIX, being used by universities, business, and
government had connecting capabilities. Most networks were the prerogative
of the major corporations, who used proprietary OS on really expensive
computers. Novell and Banyan were two of these. The hardware portion of
these networks were big and expensive, as was the OS. The installation
and maintenance was technical and expensive as well. There was, however,
a networking OS protocol running in the background, that would become the
basis for today’s network capability. More on this later.
The home or small business user was left in the cold. Microsoft, in
it’s follow-on OS systems began to provide various levels of network capability.
The PC world that most of us knew had to wait for Windows 3.x including
Windows for Workgroups and the Windows 95/98/ME OS series to gain this
network capability. Microsoft developed a series of business OS applications
that are really network ready in the later part of this period. NT/2000/XP
OS systems fall into this category. The Apple OS systems had network capability
in this time frame. The hardware side of the network equation, NIC, hubs,
switches, and routers began to be built and priced so that the home and
small business user could afford to install networks and leverage the capability
of several PCs. Computer technology also developed so that the power of
the individual computer could match early mainframes.
Also, as the technology of the Internet and other large scale networks
became available, that technology fed into the PC, making it a real communication
tool. Advances in connections to the Internet, i.e., broadband telco DSL
and cable television Direct Cable moved all of us away from analog modem
connections and the speed limitations of the analog telephone system. The
increased bandwidth of broadband made it possible for more than one computer
at a single location to be connected to the outside. This multiple use
communication capability literally propelled the home and small business
user into networking. The broadband bandwidth gave individual users the
same multiple use capability that big business had in the early computing
where they used leased lines and expensive T-1 connections. Individual
broadband also drove the networking components (routers, NICs, hubs, and
switches, etc.) prices down. Manufacturers have been able to bring the
price of network components to within everyone’s reach due to the large
numbers of individual and small office users.
Basic Network Technology
The basic physical and concept layout of networks include the medium
(means of data transfer, i.e., cable, radio transmission, etc.), access
control method (OS protocol), transmission technique (broadband, or baseband)
data rate, and network operating system. The primary function of networks
is to provide data and resource sharing capabilities to everyone on the
Data and resource sharing includes two definitions that must be understood
to really understand networks. Data sharing is straight forward. Data can
be shared in any number of ways including copying to a floppy and hand-carrying
it to the intended user, or it can be transmitted electronic means, i.e.,
the network. Digital files created at one computer can be shared with other
computers on the network. Digital files can be anything that is digitally
generated, documents, spreadsheets, databases, forms, applications, or
Resource sharing is a little different in that a resource in computer
terms is anything that is available in the computer or network. A resource
can be a physical device such as a printer. It can also be a virtual device
such as a virtual storage capability. We mainly think of physical devices
such as hard drives, printers, CD-ROM, modems or scanners. The shared resource
on the network such as a printer can usually results in an overall cost
savings to the network owner in that everyone on the network can use that
shared printer or other resource. Data safety is also enhanced using a
network to store the data on more than one location.
The means of data transfer or media refers to the method of data communication.
This media may be a cable, radio frequency, or other electronic method
of sending and receiving the data. The cable may be a direct connection
from one serial port to another via a null cable. The cable may be high
quality twisted pairs that meet certain standards such as Category 5 Ethernet
cable or it may be coaxial like TV cable. Fiber optic cable is used in
very high speed data transfer situations. And, the data can be transmitted
and received by radio frequency network methods.
The access control method is found in the OS protocol that controls
how data moves through the computer. Within the OS, a structured standard
is included called the OSI Model (Open
that consists of seven layers that perform how the data will flow through
the computer and network. All network ready OS systems must conform to
part or all of this model. Each layer of the model is interconnected to
the layer on each side if it to handle how the data is addressed and packaged
for transmission and receipt. Each layer specifies how the hardware and
software interacts also. Every computer or node in the network must recognize
and utilize the same OS protocol.
The transmission technique governs how the data is handled as it flows
from sender to receiver. The network standard specifies how fast and in
what form. An Ethernet network, for example, specifies what the hardware
and software shall do at each stage of the data transmission. Ethernet
NICs, cable, and other devices are required. The network OS protocols handle
and prepare the data to meet the Ethernet processes.
The standards specify how the network is arranged. The layout aspect
of the network concerns how the network computers or nodes are connected.
This is called a network topology. The topology refers to the physical
and electronic connections. An Ethernet network topology, for example,
is usually configured in a star arrangement. All of the nodes or hosts
(computers) in the Ethernet network are connected to a central point, usually
a hub or switch, which acts as the traffic director for the data flow.
Other topologies include token ring and fiber networks that are arranged
in rings in which the data flow travels in a ring to its destination. The
Ethernet, for example, standard is described by IEEE 802.3 and covers how
the data is handled at each stage of its movement as well as what the data
rates will be. Ethernet data rates are from 10 Mbps to 100 Mbps. The IEEE
802.3 standard is being modified to let the data rates move to Gbps.
The home and small office network can expect to operate at 100 Mbps
within it’s LAN. It’s outside connection is governed by the speed of the
outside network, i.e., DSL at 1145 Kbps downstream/ 142 Kbps upstream or
Cable at 2723 Kbps downstream/ 332 Kbps upstream. (Data from actual tests
on my two connections during a previous test. April
2002 Comm Corner column.) The combination of bandwidth and speed that
is available to the home and small business user is the basic factor that
makes a home or small business network feasible. The bandwidth can be shared
by all the computers in the network.
Network Hardware Components
Hardware requirements in addition to the computer include the NIC,
and possibly a hub or switch. In the beginning, the NIC was a add-on card
to either a ISA or PCI slot on the MB (MotherBoard).
Now the NIC can be a built-in port on the MB. The Ethernet IEEE 802.3 standard
specifies how the NIC is designed and what protocol it will recognize from
the OS. The plug-in connector must also be specified for the unit to work.
The most common Ethernet female connector ports are designated as RJ 45
and can receive eight wires from the cable plug. They look like a very
large telephone connector. The NIC is specified as 10BaseT or 10/100BaseT.
This indicates the bps (bits
second) the unit
will transmit or receive data.
Ethernet cabling is specific and requires four twisted-pair cable, either
shielded or unshielded. Shielded cable is very expensive, so the most common
cable is unshielded and is called UTP (Unshielded
Pair). The cable
is of high manufactured quality known as Category 5. The cable is terminated
at each end with RJ 45 plugs so that the eight wires are arranged in a
specific order. UTP Cat 5 cable will transmit or receive at up to 100 Mbps.
A companion part of the IEEE 802 Ethernet series standard allows for
radio frequency as the transmission medium. This part of the standard is
known as IEEE 802.11 series a or b. The 802.11b standard transmits and
receives at up to 10 Mbps.
The next two pieces of hardware that can be required are Ethernet 10/100
hubs or switches. A hub is a device that directs the computer traffic within
the network. A switch is a smart hub. The cable from each of the computers
is plugged into a receiver connection in the hub, which then redirects
the traffic from the sender to all the receivers. The switch knows which
computer to send the traffic to and directs traffic only to the proper
One additional hardware component in the network, especially with broadband
an outside connection is a router. A router is a device that knows what
addresses are within the network and what address is at the other end of
the broadband connection and can direct traffic to the proper receiver.
Most Ethernet broadband routers have a built-in switch, either two or four
RJ 45 ports.
Broadband routers also provide a level of security to the network. Broadband
connections, DSL or Direct Cable, are open all the time the computer or
router is running and is connected. This can be a source of unauthorized
entry into the computer or network. The broadband router has built-in utilities
that protect against this unauthorized entry in the form of IP (Internet
Two IP utilities are available in most of these routers. IP NAT
NAT provides a single IP address to the outside world while allowing multiple
IP addresses inside the network. DHCP is a service that assigns the internal
IP addresses to all the computers or hosts inside the network. The network
ready OS has the ability to assimilate the IP address assigned to it from
the DHCP server service in the router.
Network Software Components
In order for an OS to be network ready, it must have the OSI utilities
that are referred to as protocols. These protocols direct the data handling
at each stage of the transmission and receipt. Addressing and packet handling,
the technique of breaking the data into usable byte sizes for transmission
and receipt, are done by the protocol. The default standard that is universally
used today is the TCP/IP (Transmission
standard developed for the Internet. This protocol is included in
nearly all OSs being used today. Windows 95/98/ME/NT/2000/XP are equipped
with the TCP/IP protocol suite. Apple, Novell, UNIX, and Linux also contain
this protocol suite. This universality use of this protocol means that
all computers containing it can talk to one another regardless of the basic
OS. The IEEE Ethernet standards recognize this IP protocol suite.
The IP protocol suite is based on a number scheme for addressing each
host in the network. This addressing scheme makes each host unique as it
is the only address in the network. Each host and the router know who is
on-line at any given time. Some addresses are Internet ready and can be
recognized by any computer that is on the Internet. Others, used primarily
in the DHCP portion of the router service are not readable on the Internet,
but are readable within the local network.. This is part of the security
set in place by the router. The NAT service is able to translate the outside
Internet ready IP address into the proper internal IP address.
The OS that is network ready can be used in simple or complex networks.
An example of a simple network would be two or more computers so that each
computer is equal to the next. This is a peer-to-peer network and provides
for file and print sharing. Each computer or host in the network must know
the other computers. If there is an addition, then each host must update
its addressing scheme to recognize the new host.
Other networks operate as server/client nodes in the network. The network
OS in this situation operates either as a server, in that the computer
running the server OS waits for other computers, clients, to ask it to
do things. These functions are varied, file storage, printing, security,
DHCP, e-mail exchange, virus protection, firewalls, application service,
and database warehousing to name a few services. The client hosts in the
network, on the other hand, function as the user hosts to do word processing,
spreadsheet handling, graphics, accounting, gaming, and just about any
other function that is required by the users. OS systems that fall readily
into this category are the Windows NT/2000/XP series, UNIX, Linux, and
the proprietary network OSs such as Novell.
Advantages and Disadvantages of Networks
The major advantage of using a network is that the network leverages
user’s ability to communicate with other users. The network provides efficiencies
in that each computer does not have to have a printer to print, large storage
for data, backup capability, or a modem to communicate. A shared printer
is available to all the users on the network. It can be connected to one
computer or can be node on the network as a network ready printer. That
one printer or like device can handle the work of all the users on the
network. The storage of data can be installed on more than one computer
or server so that there is less chance of losing it. Failures do happen
and there is better chance of recovery if the data is located throughout
the network. Using a server as the data storage location, only one machine
must be backed up as all the data can be stored on it. The increased bandwidth
afforded broadband connections coupled with a network allows more than
one user to surf the Net or send data or e-mail.
Disadvantages of networks include greater complexity, more chance for
problems to occur, and some increased cost in the initial installation
as the network components must be accounted for. Networks can be complex
and need some technical expertise to setup and operate. Problems do occur.
The network can crash. More components in each machine mean that more can
In the final analysis, the advantages far outweight the disadvantages. The leverage gained by networking greatly increases the communication that users may exercise.