There are many network layouts, referred to
as topologies in computer-speak, that have been used through the
years. By far the most common topology used today is the star
topology. In a star topology all the computers have a connection to a
central point, which acts like a switchboard, passing information from one
computer to the other.
There are three types of devices that can
be this central point: a hub, a switch, or a router
(the differences between these three aren't important to this
discussion). Today, the most commonly used device for the central point
in homes and small businesses is a router, so that's the term that will be
used throughout the rest of this page.
Your router talks to an adapter on your PC
called a NIC - Network Interface Card. Your NIC and your router
are connected via a cable or, in the case of
wireless networking, via radio waves.
So if you have a router, and you have
computers connected to it, you have a network.
Once a connection exists between the router
and all of the other devices (computers, printers, etc.) data can be
passed back and forth between the devices by passing the data through the
router. How does one computer know what data to send, and when to send
it, to another computer? Today, especially with the internet, most
networking is based on the client-server model, which means you
have one device that is sharing something (that's the server) and another
device that asks to use that shared something (that's the client).
Probably the best known example of this is
the World Wide Web. Let's take the webpage that you're reading right
now. This webpage is actually a file sitting on a PC connected to the
internet. That PC is doing two things, it's willing to share this
particular file and it's running some server software. These two things
make that PC a server.
Your PC is connected to the internet and is
running a browser (which is a type of client software), something like
Internet Explorer or Firefox. When you click on the link that leads to
this webpage, your browser (the client) sends a request over the internet
to the web server (the server) that holds the page, asking for the page to
be sent back. The server sends the page back over the internet to the
client, which then displays the page in its window.
The client in the client / server model
isn't always the one getting the data. The client can also be the sender
of the data. Let's say you have a computer that's sharing a printer,
making it a print server. When you want to print from another PC to that
printer, your client sends the data to the print server to be handled.
Remember, it's not which way the data travels that distinguishes a client
from a server (since most of the time there's data traveling in both
directions) but which device is sharing a resource (the server) and
which is using the resource (the client).
One final, common example is a file
server. One computer on the network shares at least one folder. The rest
of the computers on the network can access and update the files in that
folder. An example of this in a business where several staff members may
be working on a the same report. Another example is a home network where
the folder that music files have been saved in is shared, potentially
allowing any other computer on the network to play those music files.
Unfortunately, there are people out there
who, for whatever reason, can't be trusted. So even though there's a
great deal of convenience when you share things over a network, you have
to be thinking about security. Luckily, building a secure network isn't
that hard to do, but if you'd like our assistance making your network more
secure, contact us today for a free estimate.
The first step in securing a network is a
firewall. Understanding how a firewall works is easier if you compare a
firewall to people using cell phones in a magic room.
Imagine that you take your cell phone to a
room where, once you are inside, you cannot receive incoming phone calls
from outside the room, but you can make outgoing calls. Once you dial
someone outside the room and they answer you can carry on a conversation
just like any other phone call, but since they are outside the room you
have to call them, they can't call you. Now let's imagine that if more
than one person is in this room with their cell phones they can call each
other, and they can call to anyone outside the room also. In other words,
nobody outside the room can call a phone inside the room, but the people
inside the room can call anybody whether they are inside or outside the
room The room doesn't block phone calls, it only blocks incoming
phone calls.
This is exactly how a firewall works.
Let's run through an example. Say you have two computers attached to a
router. The router is also connected to the internet via either a DSL or
cable connection. Your router probably has a built in firewall that works
(if you've connected everything together correctly) like the magic room
described above. The two computers are "inside" the firewall (like two
cell phones in the magic room) and the internet is "outside" the firewall
(like all the cell phones outside of the magic room). Now you open a web
browser on one of your computers. It initiates a session (makes a phone
call from inside the room) with a web server on the internet (a phone
outside the room) and data flows in both directions.
Let's say, further, that you have a shared
folder containing music files on one of the computers, making it a file
server The other computer can bring up a client and play those music
files because both computers are inside the firewall, just like people
inside our magic room can call each other.
But if a computer from the internet,
outside the firewall, tries to access those music files, they can't. The
file server is still sharing the files, but computers on the internet
outside the firewall are blocked from initiating a session with a computer
inside the firewall, just like phones outside the magic room were blocked
from making phone calls into the room.
There's a lot more to firewalls, but the
above gives you a basic understanding of how things work. One last point
about firewalls: there are two places where you'll probably encounter
them. One is in the router as we've been discussing, and the other is a
software firewall inside your computer. All of the recent versions of
Windows come with a firewall, and if you have any antivirus software
running it might have replaced the Windows firewall with its own. These
software firewalls work exactly like the firewall within your router.
If you're concerned about the security of
your network, contact us today and let us
provide you with a free estimate.
Wireless networking is exactly what its
name implies - networking that doesn't use wires but instead uses radio
waves. Just like wired networks, most wireless networks have devices that
speak to each other through a central device called an access point.
In a home or small business an access point is usually built into a
router, making it a wireless router. On the PC side you also need
a wireless connection (referred to as a wireless NIC). Most newer
laptops come with an integrated wireless NIC, but older laptop and
non-laptop PCs might need to have an adapter added, usually a USB device
or a PCMCIA card.
Just because it's called wireless
networking doesn't mean they are exclusively wireless. Usually a
wireless router has wired network connections and an antenna for wireless
networking, and both the wired and wireless networking occur
simultaneously.
One confusing area of wireless networking
is the compatibility of the many standards that exist. Wireless
networking is governed by the 802.11 set of computer standards, each
standard being given a different letter suffix, so you have the 802.11a
standard, the 802.11b standard, and so on. When you purchase a wireless
router or NIC they will be labeled with which standard they support. Many
times the standard will only be referred to with the suffix letter, so
you'll see something labeled as "wireless G" meaning the 802.11g standard.
There are four standards that you need to
worry about when purchasing wireless routers or NICs: a, b, g & n. Here
are two charts showing what is compatible with what:
| This
wireless router ... |
...
will work with these wireless NICs |
| 802.11a
wireless router |
802.11a wireless NIC
802.11n wireless NIC |
| 802.11b
wireless router |
802.11b wireless NIC
802.11g wireless NIC
802.11n wireless NIC |
| 802.11g
wireless router |
802.11b wireless NIC
802.11g wireless NIC
802.11n wireless NIC |
| 802.11n
wireless router |
802.11a wireless NIC
802.11b wireless NIC
802.11g wireless NIC
802.11n wireless NIC |
| This
wireless NIC ... |
...
will work with these wireless routers |
| 802.11a
wireless NIC |
802.11a
wireless router
802.11n wireless router |
| 802.11b
wireless NIC |
802.11b
wireless router
802.11g wireless router
802.11n wireless router |
| 802.11g
wireless NIC |
802.11b
wireless router
802.11g wireless router
802.11n wireless router |
| 802.11n
wireless NIC |
802.11a
wireless router
802.11b wireless router
802.11g wireless router
802.11n wireless router |
One important note about the above
chart is that the when you mix devices from different standards you'll
usually get the performance of the slower standard. So, for example,
802.11b devices have a maximum speed of 11 Mbps, and 802.11g devices have
a maximum speed of 54 Mbps. If you have a wireless router that is 802.11b
and a wireless NIC that is 802.11g (or vice versa) you'll only get 802.11b
speeds, or a maximum of 11Mbps.
If you'd like our assistance setting up a
wireless network, contact us today for a free
estimate.
The appeal of wireless networking is in its
convenience - you can have your laptop anywhere within range of your
wireless router and still access the internet. The problem with wireless
networking lies it this same fact. More than likely you can connect to
your wireless router by sitting in your car parked in front of your house,
and if you can do that with your laptop somebody else can do the same
thing with their laptop. And, by accessing your wireless router they are
inside your router's firewall and therefore can
potentially get to any shared files you have on other computers inside
your firewall. If you're going to have a wireless network you need to
implement some wireless security by using some form of encryption.
There are four levels of wireless
encryption for homes and small businesses:
Here's what each means:
Unsecured: No encryption is
enabled. Anybody can connect to your network as long as they are within
range of your wireless router.
WEP: WEP was the original wireless
encryption industry standard. Unfortunately, is was based on a simple
algorithm and can be cracked easily by anybody who wants to spend a few
hours learning how. While WEP is better than an unsecured network, it's
not better by much.
WPA: After WEP was cracked, there
was a move to create another industry standard that was more robust.
Industry standards, however, take a while to get ratified and there was an
immediate need. WPA is an unofficial, de facto standard for wireless
encryption and is significantly better than WEP.
WPA2: The official industry
standard for wireless encryption, it is stronger than WPA.
Most newer wireless hardware will support
all four options. Some older hardware will only support WEP or WPA.
One more note: WPA2 uses a more intense
encryption algorithm than WEP or WPA, so some older wireless hardware
slows down if you use WPA2.
There's more to wireless security than
what's been covered here, but encryption is the first step for securing
any wireless network. Don't leave your wireless network unsecured, and
don't kid yourself by securing your network with WEP, use WPA or WPA2.
If you'd like our assistance in making sure
that your wireless network is secure, contact us
today for a free estimate.
Contact us:
Oakland Solutions, LLC
55 East Long Lake
PMB 371
Troy, Michigan 48085
Phone: (248)689-1439
Email:
info@OaklandSolutionsLLC.com
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