Questions about Wardriving (or Wardriving 101)

RoadClosed,
I'm still digesting what you said in your post. I'm a little slow at picking up certain things. Usually I have to read and re-read something quiet a few times before it "sticks". In any event, I do believe I got the jist of your reply. Correct me if I'm wrong though.
**note:I put what caught my attention in bold

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In the 802.11 application, the term bursting in this case is nothing more the channel hopping (in my opinion). The data is continuous; however, a channel is only active for a small amount of time and then it switches to another, then another in a seemingly random pattern but it is not random

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You wait until its your turn and burst a few thousands of a second worth of stuff and then you stop. Then a few more thousands of a second later you do it again

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But while you are stopped another channel sends the data in a continuous stream

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From what I read here, it appears as though wireless routers do transmit continuously by utilizing multiple channels in a rapid (seemingly random) succession.

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The beacon doesn't even come into play. It operates in frames and frequencies outside the data stream.

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This is why I still have some learning to do. I obviously haven't grapsed the concept as of yet. Thanks for the details though.

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Okay, gotcha, I know and understand EXACTLY what you are talking about now. Yes, I do have a PCMCIA slot, and yes, the usb cable with usb card is perfectly clear to me now. Thanks for being patient there So I just ask the for any usb card? And if that's the case, could I just take the usb receiver that I use for my wireless mouse, hook that up to a usb cable, plug the cable into my usb port and I'll have an external antenna? Or will I need a different usb card and the one I use for my wireless mouse not good enough and/or do I need different software for it?

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You should try out your internal card before getting another one. See how that one performs.
As for the USB... you can't use your mouses receiver. It works a completely different way.

The USB 802.11g/b card will be about the size of a usb flash drive or pack of wrigleys gum. It may get as big as a pack of smokes depending on which brand you buy. The antenna is actually built into it. The come with a USB extention cord. I think its only 6 or 10 feet. If you need longer, you can buy another extension cord. Some of them use the usb printer style cables, some of them use the flat end.

The card should come with the drivers for at least windows. Maybe MAC. You'll have to look on the box or CD it comes with. The software that comes with it will manage the card itself. If you are going to use it on linux, you'll have to get different drivers and different management software.

Check out the sites of the tools you'll be using to determine which card(s) are compatible with the tools you'll be using. I've had good luck with netgear wg511, which uses the prism54 drivers. The netgear wg511 is PCMCIA and does not have an external antenna. The netgear ma111 is a usb 802.11b card and I've only gottent that to work under windows, not linux. A lot of people like cards that use the prism2 or orinoco chipsets because they are supported under linux and for most wifi tools, either windows of linux.

http://www.google.com/search?hl=en&l...upported+cards

Check out other tools that you might use. So far, I've gotten most things to work with the prism54 drivers. I've even gotten netstumbler to work on a broadcom internal card. You'll just have to do some research as to which cards are more widely supported for the operating systems and tools you'll be using and make a decision on that.

RoadClosed:

I read that article and I understood everything that was said in it. That is an excellent tutorial by the way. But yes, that is excatly what the wireless router is doing with beacon intervals, burst transmissions.

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access points periodlically send beacons. You can set the beacon interval through the access point configuration screen. In general, the beacon interval is set to 100ms

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A typical beacon frame is approximately fifty bytes long, with about half of that being a common frame header and cyclic redundancy checking (CRC) field.

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Beacon interval. This represents the amount of time between beacon transmissions.

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What this is telling me is that the router is sending out a transmission approximately fifty bytes long, stopping for 100miliseconds, the sending (bursting) out another transmission. This is exactly what we were doing when we would send out digital traffic over an encrypted frquency, but at a much faster rate. Our would burst for about 2 seconds, stop for about 2, then burst again for another 2, which is what I believe the cyclic redundancy checking (CRC) field in the beacon frame is for. To let itself know that the station being broadcasted to has or has not received the data, so it knows whether or not to continue sending that beacon frame over and over again or not, because with the digital terminal equiptment we were using, if the scout team we were trying to send the traffic to did not have their DTE up or not configured correctly, it would keep sending the burst transmission for about 5 trys then stop displaying an error message. If they did have their DTE up and configured correctly, it will only burst twice.

Burst transmission
From Wikipedia

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In telecommunication, the term burst transmission has the following meanings:

1. transmission that combines a very high data signaling rate with very short transmission times - i.e. the message is compressed. This is popular with the military and spies, who wish to minimise the chance of their radio transmissions being detected.

2. Operation of a data network in which data transmission is interrupted at intervals.

Note: Burst transmission enables communications between data terminal equipment (DTEs) and a data network operating at dissimilar data signaling rates. Synonym data burst.

Source: from Federal Standard 1037C and from MIL-STD-188

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In the 802.11 application, the term bursting in this case is nothing more the channel hopping (in my opinion).

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Multi-Channel Multi-Hop Wireless Networks with
Single-NIC Devices

Bursting and channel hopping (or frequency hopping) are two different things. Digital Terminal Equiptment will burst a set ammount of times on a channel (freq.), then jump to another channel, burst set amount of times, jump, bust, jump, etc.

Apparently this can be done, as well, using Multi-Channel Multi-Hop Wireless Networks with Single-NIC Devices (PDF/Adobe Acrobat), but I am not getting a clear idea of how it works as of yet, I haven't finished reading the article yet. But so far from what I understand is that it is one wireless network using, for an example given in the article, two AP's broadcasting simutaneously but each on different channels, but I can't see as of yet how that would constitute as channel hopping. Again, I have to finish reading the article.

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By increasing the beacon interval, you can reduce the number of beacons and associated overhead, but that will likely delay the association and roaming process because stations scanning for available access points may miss the beacons.

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Would this make your wireless LAN less vulnerable to attack? And can you configure your router to do this automatically when not in use, without just switching off your router, to reduce the chance of someone stumbling onto your network?

Excellent research!! We could argue the term of Burst into very finite detail. Bursting a little "hello" message on a single control channel does not constitute a burst communication system in my opinion. An example of one would be Meteor Burst. It's is a burst communication system with very LOW data rates because it takes so long to assemble a whole message. Why? You are bouncing data of little tiny meteorites flying into the atmoshphere. Cool ****. I would not call Wi-Fi a burst communication device. In fact the definition you posted supports my explaination where data is transmitted at intervals. In the whole picture wireless data jumps around frequencies but the data is continuous. Burst communications system stop all data while certain characteristics are met.

Here look at meteor burst: link to public description . Imagine a machine that tracks meteoites, finds a good probability, bursts communications components off at them and re-assembles the highly secure data? Scary **** the GOV uses. Note that there are windows lasting only a few seconds to get the data sent and decoded, then we wait until another opportunity exists. A beacon is like a light house, it is a timed signal to detect ships in the harbor at precise time intervals as they are illuminated as the light passes. Or for a ship to see the shore, or a WAP. "Hi welcome to Hong Kong harbor" :) You can call Wi-Fi t burst if you want. I was just interjecting another point of view. :D

Oh looking at the definition again... Another example could be a satelite interface controller fixed to a polar orbiting satelite. That sat will only be overhead for say 4 minutes and you wont see it again for a while. So one may highly compress data and burst the hell out of the transponder when it is at apogee. Maybe a few seconds. Then wait...... until our friend comes back arounds and BLAP. (that is my sound effect for bursting).

Not all wireless connections channel hop regularly. Those only hop when interference occurs. The systems are smart enough to detect degredation in transmission signal and issue a command to re-tune or change channels. I haven't actually looked at the 802.11 signal.

Would increasing the beacon make the WAN less vulerable to attack? No. It may make you less noticeable to war drivers. It certainly reduces overhead, but I have yet to see a bogged down wireless network. The bottlenecks are usually in the hardline connection. It will also take longer for a valid user to associate with the network. As for stopping beacons when not in use, yes definitely. Many routers support the ability to "sleep" the router. That is most likely already built in waiting for someone to enable it, but there is no way to test it because it is listening and as soon as you flip on a card in your lappy or desktop it wakes up. Come to think of it that is true if some war driver passes by broadcasting a scan?

I just got finished reading that article about meteor burst, and all I have to say is: Scary ****, no doubt! How in the hell do they come up with or even think of this stuff??? That is truly fascinating and who would have ever thought of that or even came up with the concept of that idea just blows my mind away.

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I was just interjecting another point of view.

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You know what? After reading what you had to say, I started rethinking and questioning my point of view, because as you said with the satelite example:

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So one may highly compress data and burst the hell out of the transponder

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And after going back and looking at what Wikipedia had to say about burst transmisions:

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transmission that combines a very high data signaling rate

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Then me thinking of my use of burst transmissions with DTEs and thinking about how it was an intense, short approximate 2 second burst transmission that stopped once it reconized that the other DTE that it was transmitting to received the data or after a short time period elapsed recognizing that the other DTE was not receiving the data,
and then going back and looking at the definition again:

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transmission that combines a very high data signaling rate with very short transmission times

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My thoughts now? You were right :D Because as your first article states on the compostion of a beacon frame being a transmission of approximately 50 bytes (not highly compressed data/high data signaling rate) and stopping for only 100miliseconds between beacon frames (not very short transmission times). A burst transmission is sent only when needed to relay traffic and ceases sending the transmission when A) the transmission is received by the other station, or B) it is not received after a set period of time. Where as an AP is constantly broadcasting a signal, even if the station is sleeping, and in fact, as the article stated, even if the station is awake, and you were to decrease the beacon interval (increasing the data flow), it would produce a substantial ammount of overhead, even if the station was receiving the signal.

So now that means I have to go figure out what the cyclic redundancy check field in the beacon frame is really for. Damnit RoadClosed! You were right, lol :D

So, I guess after all that, that would constitute the signal coming out of an AP as Streaming? (first def.; see also packets in that definition of streaming. It practically nails beacon frame down to a T) And not a burst transmission? Streaming came to mind after being forced by someone to re-evaluate what then type of transmission really was being used. I won't mention who forced this drastic change of view upon me (cough, cough...RoadClosed!...cough) though, lol.

You think meteor burst is scary in it's brilliance? Try this on, it was concieved in the 1940s! This is 2005. And the original protypes where Canadian. :)

elkgrin

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You must spread your AntiPoints around before giving it to RoadClosed again.

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http://inventors.about.com/library/weekly/aa090100a.htm
Made In Canada - Canadian Inventors and Inventions

http://www3.sympatico.ca/taniah/Canada/things/
Canadian Things

Meteor Burst isn't on those lists, but they had the first decent working protypes.

Candien invention: "prosthetic hand" that comes in.... um HANDY. he he.

The experimental system was called JANET. looking for link....

First Hit

Greetings all... I may be a little behind the power curve on this and for that I apologize, but I have a comment in regards to the original topic of Wardriving. I am currently deployed to Iraq and I use a Linux Knoppix laptop as well as a Windows XP Pro laptop so I can check for active and passive signals (as mentioned earlier in this thread) and they [the 2 laptops] work great with a 3Com Wireless G card (PCMCIA). However, I have heard no mention of what you guys are using for Packet Sniffers, or any at all? I guess in my position I have to sniff packets to ensure nothing sensitive is being passed (potentially intercepted). Personally I use Ethereal. I was just wondering what else you all might use.

Kismet