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Mark's Notes on Wireless Technology
 
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After considering my own goals for an in-home network and Internet access, I decided to jot some notes here to help/encourage you to use this technology.

If you detect mistakes or important concepts that I left out, please send me a note (my email address is at the bottom of each page).

Consider Wireless

If you have not done so yet, consider buying an inexpensive wireless setup for your apartment/home. It's cheap, relatively easy to setup (for the basic setup) and VERY VERY handy. To be able to use your notebook while sitting on the couch, or at your table for "desktop" space, or on the porch on some beautiful afternoon definitely has its benefits. With the VPN software from Fuqua, you can access school storage from your lawn chair.

In this document, I will give the simple basics so most anyone could set this up. Then, I will give more details for those of you who might want more complex setups for things like Internet sharing among apartments, etc.

There is a list of terms below. I can give the basics without too many arcane terms, but the details given below will require more "geek" terms.

Security

For those who might be afraid of wireless technology, don't worry. You can be secure. In the wireless world, security is very important because people CAN receive your signal, no matter what your approach is. However, you can make your data secure by using encryption. There are several options but the most straightforward one is to use basic (static) key encryption. Your data is scrambled using a key (think of it as similar to a password, but one used to encrypt and decrypt data). The wireless communication between your computer and your Access Point (which is probably your router) always uses the same encryption key. If you and another person use the same access point (router) you will all use the same key. I could intercept your signal, but without the encryption key, the data is unintelligible.

Be sure to use encryption. You definitely don't want someone to be able to see your bank information. You also don't want others to be able to connect to your router. Best case, they might download a lot of data, slowing you down. Worst case, they might do illegal activities using your connection. Encryption ensures that they cannot see your data, nor can the connect to your network.

NOTE to those who use a list of MAC addresses: This does not prevent a malicious person from SEEING your data. It is true that I could not register with your router, but I could still intercept your signal and see the data. You should use encryption, even if you want to use MAC addresses.

For those of you who wonder what the list of MAC addresses is: A router can restrict any computer from using it based on a number (Media Access Control - MAC) that each network card has. That number should uniquely identify your machine in the world. The router can have a list of MACs that it will allow to connect (or a list that it will prevent... in case you simply want to prevent ME from being on your network). This is an additional level of security that prevents CONNECTING to your router but it does not encrypt your data. So I could not get to the internet with your router, but I could still see your data. MAC addresses are somewhat easily cloned, so the security isn't super high, but it would keep out any casual user.

What Encryption Key You Should Use

Bottom line: I recommend using a 64 bit HEX key chosen at random.

First, you do not have to remember the key yourself, so use one that is complicated and very difficult to guess. I use one called a HEX key, 10 digits. Each computer stores it, and you only enter it once. Consider a randomly chosen HEX string (digits from 0-9 and letters from a-f) like 37B8C5E9A3. That would be difficult to guess so it's a good one, EXCEPT that I published it to the web, so don't use THAT one! (...and no, that's not my code :-)) Some routers will allow you to enter a normal looking password, but to me, they are often not as secure because we tend to use things easily remembered. If you chose your dogs name, it wouldn't be very secure because I might guess that. If you want HIGHER security, consider a 128 bit encryption key. We can also talk about rotating keys, etc. (which may require newer/higher line hardware)

Basics

The general goal will be for wireless access to the Internet. You will need a high speed Internet connection (via a cable or a DSL "modem"), a computer with wireless capability, a router and a wireless access point. (Note: many routers already have a wireless component to them... if so, you don't need an extra one.)

Generally, the router and wireless access point will come together. If you want to be able to connect more than one machine using ethernet (cable) then you should also be sure the unit has a built in switch (e.g. a 4-port switch).

The cable or DSL connection goes to your modem. The modem has a built in ethernet port which will be connected to your router (some cable companies will hook it straight to your computer because they don't want to be involved in wireless setups, but the better setup is to connect the modem to the router). Your computer connects to a port in the router (or the switch part of the router). If you are using a wireless notebook only, you likely must connect with a cable for initial setup. (After setup, you can disconnect and use it without the cable). For your initial setup, you use your browser to "talk" to the router. Yes, you can use Internet Explorer or Netscape Navigator to access the router directly. Instead of typing in a text URL (e.g. www.duke.edu) you will type in a number (mine uses 192.168.0.1).

Once the setup is finished, you should be able to use the network wirelessly.

If you have a desktop and a notebook, the typical setup would be for the desktop to be hooked up via an ethernet cable and the notebook to be wireless, but both machines could be wireless. (Although, some routers and other wireless hardware require an ethernet cable connection for updates to the unit (often called firmware updates)).

If you might need a range extender, be sure that your router/wireless access point is by a brand that also sells a range extender for it. The range extenders often are not compatible with other brands AND sometimes are incompatible with many models in their own brand. D-link and Linksys both make range extenders that are compatible with about three of their own routers/wireless access points.

More Detail

The switch can be used to connect up to four (or however many physical ports your switch has) cabled devices and many wireless devices, all sharing the same Internet connection.

To Strengthen Your Signal

You can use a range extender (or repeater) to strengthen your wireless signal. Warning, range extenders are often ONLY compatible with a few wireless access points of the same brand (e.g. the D-link range extender works ONLY with a few lines of D-link wireless access points). So check on compatibility before buying. This would be useful if your wireless access point is too far away to give you a good signal. This unit simply echoes the chosen wireless signal. For example, if your bedroom has the access point and you are several rooms away, you can place a range extender between the two locations (a little closer to where you will use it) and you should have no problem after that.

Some brands sell alternate antennas that increase the range of units. I don't know how effective they are.

To Make Any Ethernet Device Wireless

An ethernet bridge (to wireless) can be used to convert any ethernet device to a wireless device. (This is the same unit discussed in the section for receiving a wireless connection INTO your network.) There are often better and cheaper solutions for this task (e.g. wireless PC cards or PCI cards) but the bridge is a general solution that works for ANY ethernet device.

To Receive a Wireless Connection INTO Your Network

The most obvious way to use a wireless signal from someone else is to simply use all wireless devices and connect directly to the net available from that person. However, there may be many reasons that you might want to capture a wireless signal and send it into your own router. For example, you may have ethernet devices that are not wireless (like my printer and my desktop computer) or you may want to use your own firewall for self-directed security, or you may wish to have your devices communicate locally without affecting the incoming wireless network. To do this, you can buy an ethernet bridge (specifically, a wireless to ethernet bridge). It will allow you to receive a wireless signal which will be converted to ethernet and sent out a cable. You can then feed this cable into your router, as if it were from a cable modem. It is a little tricky and some manufacturers don't even know that it can be done (D-link's technical support told me that it is not possible, but it's working in my apartment). See a separate page on how to do this.

Security and Encryption

I strongly encourage all of you to use encryption. See my section above called Security.

Automatically Assigned IP Numbers

If you want your own network to automatically assign IP numbers, even to cabled ethernet machines (I generally do) then be sure that your router has a DHCP server.

The 802.11b vs. 802.11g decision

You can buy 802.11b technology very cheaply and for most applications it will work well. The 802.11g hardware will have a bit farther range (so I hear) and will allow components WITHIN YOUR LOCAL network to communicate rapidly. But most of you will be using the network ONLY for communicating over the Internet. 802.11b is faster than most Internet connections anyway, so you will not gain much with 802.11g technology (unless you want the better range of 802.11g).

VPN and Tunnels

VPN, or Virtual Private Networks allow you to connect to a LAN even though you are remote. This allows you to view storage areas, etc. When you buy a router, be sure it supports VPN. If I understand things correctly, VPN support allows you to have multiple tunneling so two roommates could be connected via VPN tunnels at the same time. If your router does not specifically support VPN, you are likely limited to one VPN connection.

Terms

Term Definition/Notes
802.11a A wireless standard that didn't catch on too well. It's in the 5 GHz range (I can't recall the exact frequency) and can communicate up to 54 Mbps)
802.11b A wireless standard that caught on well and who's highest speed is 11 Mbps operating in the 2.4 GHz frequency.
802.11g A wireless standard that as of 2004 is gaining popularity. It is in the 2.4 GHz range and has a maximum speed of 54 Mbps (although some companies have their own proprietary technologies that push this to 108 Mbps - they typically cannot talk to units except those of the same brand that also have that proprietary technology.)
Bridge
(or Ethernet Bridge)

A bridge allows two networks to talk... even networks that use different technologies. So, a wireless access point is a type of bridge because it takes from an ethernet source and converts the communication to the standards used in wireless technologies.

The bridge that holds the most interest for me in this case is often called an ethernet bridge and it will go EITHER DIRECTION (to ethernet or to wireless) so I can receive a wireless signal from Dariusz and convert it to ethernet, supplying my network with his resources (broadband Internet being the most interesting resource).

However, these units can also receive from a wireless signal and convert to ethernet, thus can be used to provide wireless capability to any ethernet unit (like my HP printer that has a network card).

DHCP I can't recall the acronym and am too lazy to look it up, but this is a protocol for automatically assigning IP numbers
Ethernet A network protocol that is the most commonly used. Think of it as the language of the HARDWARE parts (like ethernet cards and routers) of networks. It's what network hardware components use to talk to each other over most networks.
Firewall
(hardware firewall)
A hardware firewall is generally built into a router and it will guard what types of communication are allowed. This is generally believed to be the most secure type of protection from access from the outside world (as opposed to software firewalls like Black Ice, or Norton and McAfee Firewalls). (You can run both without a problem but generally, it will not buy any extra protection.)
IP See Internet Protocol
Internet Protocol IP is a protocol (think of it as a language that computers use to talk on local networks and on the Internet. IP must use a hardware part too (the computer must have a network card to use as its communication device (like a "telephone" if you will). Ethernet is the most commonly used "hardware type language.") IP is the most commonly used network language "spoken" by computers.
LAN Local Area Network - a local connection of many computers generally connected either through ethernet cables or wireless technology
Mbps Mega bits per second. (MBps is Mega Bytes per second)
Router

A router will route computer messages (generally using IP and ethernet) between networks. The interesting part of a router to most of us is that it will allow our home network to access the Internet, which to the router, is a second network. If the unit has a built in switch (and most do) it will allow us to hook several ethernet devices on our home network and it will "Route" all Internet traffic to the appropriate network (the second network, often provided by a cable modem).

Switch / Hub

Don't buy a hub. Buy a switch. Most of you who might want this will get it built into a router, so you likely don't need to read this. Because switches are cheap now, hubs are a thing of the past. For those who want to know the difference, read below.

A switch will join several computers on a network. Generally, each computer will have a network card and will plug into a switch or hub. Through that router, all the machines can talk. A router with computers is what comprises a network.

The difference between a hub and a switch

A hub cannot have more than one device talking on the network at the same time. A switch can do simple routing, therefore device 1 can talk to device 2, while device 3 talks to device 4. So on a busy network, switches will be much faster. Also important, a switch can mix speeds, so a slow network card on a printer (10 Mbps like that on my HP 4000N) can talk to a newer card on a computer (100 Mbps) . That's not possible with a hub.

VPN Virtual Private Network - This technology allows a remote computer to connect to an otherwise local area network (LAN).
WAP See Wireless Access Point
Wireless Access Point

WAP - or AP. This is similar to a router, but it receives a signal (generally it's an ethernet signal - and it's likely from a router) and then broadcasts a wireless signal for use by computers that are capable of communicating wirelessely. WAPs are OFTEN (but not always) built into a router.

Generally, you will want to buy a router with a built in AP and a built in switch (often it's a 4-port switch)

Good luck. If I can help, let me know. My e-mail address is below.

 

Contact Info© copyright - Mark W. Rice