Wireless Information and Discussion (pending FAQ)

Discussion in 'Networking, Telephony & Internet' started by Stanza, Aug 2, 2002.

  1. Stanza

    Stanza Member

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    Wireless 101 or FAQ.....maybe

    OK seems to be quite a few users here interested in wireless networking.

    Would all those people interested please post the questions they would like answered regarding this subject....

    I will try to answer them all, so as to get more people up and running.

    Maybe this could then turn into a sticky up top? (tho I think there is getting a few already) and if anyone else then has questions they can be pointed to that thread / sticky......hell maybe even someone could possibly upload a copy of it to a host to ease the burden on the forum?

    OK fire away......if I myself can't answer the questions, I know the gurus to ask.

    some questions from "gregzeng" in another thread

    WIRELESS networking is so new to me, that I only know what I've read about it. Seems to me that its like a 10 mbs Ethernet networking, but without the cables. Is that correct?

    Yes wireless networking is like 10Mbps normal lan (Half Duplex) speed wise....and like the name suggests it uses NO WIRES and works on radio frequencies. Currently 2 different ones 2.4Ghz and 5Ghz.

    The Harvey Norman salesman (Canberra) told me that a hardware device attached to each computer is all I'd need (both my systems run Windows XP). The notebook can take either USB or PCMCIA. The desktop can take USB. Costs start from $199 AUD for each device.

    True, to network 2 computers together you only need an adapter for each machine. to network more than 2 computers would require either an AP (access point) or one computer with a wireless adapter running in AP mode.

    The range won't be very far in whats known as ADHOC mode(2 computers in a point to point type config) as usually the antennas on say an AP are a little better (higher output) and are designed to radiate the waves horizontally in a 360 degree circle.

    Laptop style PCMCIA type cards have pretty poorly designed antennas which (because of their shape) tend to radiate up and down......and work best if the laptop is stood verticle.....not ideal for typing:rolleyes:

    USB and some PCI type adapters have the same type of antennas as AP's (little rubber ones like mobile phones) and are prefered over PCMCIA type cards if you are not planing on using any external antennas.


    I assume hardware & software security are such that intruders will find it impossible to upset my network. And that my wireless network will not upset anyone else (in a block of apartments) ?

    No wireless is very insecure, read HERE for a good guide to security and wireless.

    As for interfering with neibours etc. There are several channels to operate on (11), 3 of which are NON OVERLAPING.....so you can set a channel to operate on and should be able to not interfere with others. Just like garage door openers and cordless phones etc....Tho if everyone in your appartment gets a wireless setup it could get a little tricky.


    If I have an ADSL USB modem, I can share this modem with any user on my wireless network ?

    Yes you can, tho as above make sure it is secure 1st, or every Tom, Dick and Harry driving past could potentially use your ADSL connection !!:eek: Also check your AUP with your ISP to make sure this is allowed 1st.

    You can also get Wireless COMBO routers, they are usually like a normal ADSL / CABLE router that connects your computers to the net, with the addition of wireless networking included. Sort of an AP / Router / Switch mix.


    I can track the downloads & download speeds/ quantities for each user on my network ?

    You can do this with any network (with the right loging tools), tho most firewall type software should, possibly some routers might be able to also do this for you. Wireless is still a network with lan adapters / MAC addresses etc, it's just the physical wires that are missing

    On both ADSL & V90, the speed of the wireless network will not upset the Internet speeds with a PC networked with the modem-wired computer ?

    Erm not sure I understand that question...??:confused:

    But NO wireless won't interfere with the other forms of networking described above.


    PS anyone know any good VB code to make the above look half decent? please let me know
     
    Last edited by a moderator: Aug 30, 2008
  2. harpie

    harpie Member

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    If I already have a small home wired network. Can I plug in a wireless card into my server and into my notebook and access the whole network without any other hardware from my notebook?

    Actuallymy server is under the stairs, can I plug it into one of the other networked computers + notebook and still access the whole netwotrk?
     
  3. x0nt

    x0nt Member

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    Make the blue writing in bold and it should look great.

    I'm looking at getting a wireless network going around this neighbourhood of mine.

    I looked at a few AP's and was wondering how easy it was to attach an external antenna to it. And which card(s)/units are the best in this case.
    Same with pci adapters, which are the best for attaching an external adapter, cost is a major factor (i'm a student).

    Cheap antennas, where do you find them? Both AP and individual style.

    Cheers,

    x0nt
     
  4. gregzeng

    gregzeng Member

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    wish that the APC publication would employ journalists

     
    Last edited: Aug 3, 2002
  5. gregzeng

    gregzeng Member

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    Re: Wireless 101. MORE QUESTIONS

    > Yes wireless networking ... works on radio frequencies. Currently 2 different ones 2.4Ghz and 5Ghz

    Do we need to know about the radio frequencies? If we do, why?
    ...
    > True, to network 2 computers together you only need an adapter for each machine. to network more than 2 computers would require either an AP (access point) or one computer with a wireless adapter running in AP mode.

    Is "AP" set by the operating system software, or a special program software, or by the particular brand/ model of the hardware adapter? If I just have the 4 or 5 computers with wireless network cards, then just one of these could act as "server", as "AP". Is this what you mean?

    > The range won't be very far ... usually the antennas ... are designed to radiate the waves horizontally in a 360 degree circle.

    Earthed shields be carefully placed, in relation to the aerial & the other wireless networked computers? (An AC-powered computer is a metal, earthed shield, I think).
     
  6. gregzeng

    gregzeng Member

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    Re: Wireless 101 or FAQ.....maybe

    > No wireless is very insecure, read HERE for a good guide to security and wireless.

    How insecure? If my wireless networking operates just a few hours per day, at almost random operating times, will that give some on nough 'window' to intrude into my system? I can't imagine anyone wanting to intrude into my home computer.

    > You can also get Wireless COMBO routers, they are usually like a normal ADSL / CABLE router that connects your computers to the net, with the addition of wireless networking included. Sort of an AP / Router / Switch mix.


    I think these are more than twice the price of a USB-unit or a PCM-CIA unit. Is that so? If you want routers/ switchers, then I think that perhap you do not have a simple beginner's network.
     
  7. x0nt

    x0nt Member

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    gregzeng your posts are very hard to follow, can you set them out properly for easier reading please. Use the edit button after you have posted to fix errors and typos. The edit button also comes in handy when adding extra information, no need to reply to yourself.

    To answer your questions:

    Yes you do, there are different IEEE standards which are incompatible with each other. ie a 5ghz card cant communicate with a 2ghz card. These are known as 802.11b (2.4GHZ) and 802.11a (5GHZ). 802.11g is also on the way however this runs on 2.4GHZ and is compatible with 802.11b. 802.11b is an 11mbits standard and 802.11a is a 54mbits standard, so 'a' is faster but has one drawback, signal strength is compromised faster at increasing distances. Less bandwidih for your buddy 10k's away.

    AP stands for access point, the mode of the wireless point, not a simple switch to turn on. This is set by the hardware, controlled by internal firmware, not the OS. AFAIK all access points will run by themselves (with no OS contact), these are hardware controlled. Where stanza was talking about configuring a normal wireless card to be used as an access point, he was talking about setting your card to ABHOC (the letters look wrong here, but its irrelevent) mode. In this mode each card communicates directly with each other card requiring a connection. There is no base station acting as the main hub. This mode is slower and an Access point cant be used as a connector or bridge enabling the two clients to be further apart.

    I prefer english but hey, maybe someone can understand this. :confused:

    Most probably not, I'd bet my savings that you wont get 'hacked' within a 6 month period.

    Wireless is VERY insecure. Basically your allowing anyone to plug into your home network with ease while a wireless connection exists. The best way to combat this in my mind is to tighten up your local PC's. According to stuff I've read if someone wants to get in they will. There is no security tough enough (bar some very expensive cisco gear). As long as you dont leave ports open allowing serious access to your local machines you should be right. Dont leave WFS access on for guests, always make sure it requires authentication. Dont use NT 4.0 or Win9X they are so full of holes anyone can hack it, maybe not WIN9X but NT4 I wouldnt touch with a 40 foot pole. Set up your router to allow only access from the mac addresses you specify. Same goes for ip addresses. Dont use DHCP or the default LAN ip's. If you know enough about box security you should be fine. WEP-40 can be hacked in a matter of hours and I'd assume within an hour for an expert. It's upto you if you want to use it, it does come with a performance hit.

    Of course they will cost more, they provide extended functionality.
    Does it matter if you dont have a simple beginners network ?

    Cheers,

    x0nt
     
    Last edited: Aug 3, 2002
  8. gregzeng

    gregzeng Member

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    Re: Wireless 101 or FAQ.....maybe

    On both ADSL & V90, the speed of the wireless network will not upset the Internet speeds with a PC networked with the modem-wired computer ?

    Erm not sure I understand that question...??:confused:

    But NO wireless won't interfere with the other forms of networking described above.


    In the "old days", networking had to be wary of IRQ's ... there were a limit on them and a lot of conflicts that even Windows 9x could not sort out. I was wondering if wireless networking has these same problems, even with WINDOWS XP.

    What I find amazing is that ADSL MODEMS seem so complex. But I'll check the discussions there later.

    Wireless networking, memory speeds and the mny data streams inside the computers -- I'm hoping that Windows XP is ok with it all. I read that some 3D graphics will overload the software & graphics of low-cost computers. Add networking complexities to that, & I'm not sure what happens.
     
  9. gregzeng

    gregzeng Member

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    YOUR MESSAGE LENGTH IS 2955 CHARACTERS

    >
     
  10. gregzeng

    gregzeng Member

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    Does it matter if you dont have a simple beginners network ?

    > 802.11b. 802.11b is an 11mbits standard and 802.11a is a 54mbits standard, so 'a' is faster but has one drawback, signal strength is compromised faster at increasing distances.

    Besides all these numbers, I think there is a more USER FRIENDLY label? Fast, Wide ?? "Wireless Ethnet" ?

    > about box security you should be fine. WEP-40 can be hacked in a matter of hours and I'd assume within an hour for an expert. It's upto you if y want to use it, it does come with a performance hit.

    > Of course they will cost more, they provide extended functionality.
    Does it matter if you dont have a simple beginners network ?

    Yes. I don't want to be involved with anything but a simple beginner's network. In that regard, I'm like the vast majority of the users of computers.
     
  11. x0nt

    x0nt Member

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    gregzerg your english is very hard to understand. Take your time when you post. Why dont you type your post into word and let the grammar and spelling features fix up your post. The fact that you are used to the 'old ways' have nothing to do with stringing a sentence along that makes sense.


    This should be re-worded to
    Besides all these numbers are there more user friendly labels?
    Answer: No, its rather simple. '802.11' means wireless. There are three letters to think about, a, b, and g. They add onto the end of 802.11.
    "g" can be ignored as that hasnt been released yet.
    "a" is the 5ghz standard at the faster speed.
    "b" is the oldest and most accepted standard running on 2.4ghz (same as your microwave and household telephone), this the slower wireless.

    So all you have to remember is that b is slower, cheaper and widely used at the moment. a is faster, just came out and is more expensive.
     
  12. gregzeng

    gregzeng Member

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    > gregzerg your english is very hard to understand. Take your time when you post. Why dont you type your post into word and let the grammar and spelling features fix up your post.
    ...
    Sorry. Before I went to the University of Adelaide 34 years ago, I only got a B-level pass in English.

    I used to used grammar & spelling features of WordStar when I used WordStar & CPM. When I'm not professionally editing, I don't use this computer checking.

    > So all you have to remember is that b is slower, cheaper and widely used at the moment. a is faster, just came out and is more expensive.

    In the July issue of Australian Personal Computer, their expensive, color full page advertisements used "USER FRIENDLY" descriptions that - I think - were about "Wide" or "Fast" wireless ethernet. I read the magazine several hours ago in the local library. Perhaps someone else can clarify my misunderstandings, by looking at the actual advertisements.

    [984 characters length !!]
     
    Last edited: Aug 3, 2002
  13. Foxster

    Foxster Member

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    The other way around this problem is using wireless cards the incorporate encryption. This way, you can use DHCP if you like and you don't need to tighten your security any more than you normally would as it is very secure. One thing I have to point out though is that the wireless cards that do incorporate encryption are more expensive.

    As an example of how insecure wireless is (without encryption), a friend of mine has a laptop and a wireless network card, he went for a drive and found more than 20 access points within a 10 min drive of his work and only three of them used encryption. When he was within range of the non-encrypted AP's his computer automatically obtained an IP address through the DHCP on the servers and if he had wanted to, he could have had access to network resources without any trouble at all. The thing is, he only discovered this by accident, he had his laptop turned on in the car and it started beeping when it logged in on the non-encrypted AP's and he found he was online! It was that easy, he didn't have to do anything as DHCP automatically hands out IP addresses to any machine that connects to the network and without encryption on the wireless signal, anyone could have connected up. Needless to say, it's also a good idea to secure your system (close unused ports, etc) just to be sure that if anyone does get in, they can't do anything malicious.
     
  14. x0nt

    x0nt Member

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    WEP. The encryption standard is basically fucked. There is an article on ArsTechnica somewhere that explains the faults with WEP. If you can get 128bit WEP then get it (aka WEP2), the encryption is better, instead of hours to break it (as with 40 bit), it should take weeks and weeks. If you can get it and then use it, security should be fine.

    Have a look here for information on why WEP isn't secure.

    Also:
    We implemented an attack against WEP, the link-layer security protocol for 802.11 networks. The attack was described in a recent paper by Fluhrer, Mantin, and Shamir. With our implementation, and permission of the network administrator, we were able to recover the 128 bit secret key used in a production network, with a passive attack. The WEP standard uses RC4 IVs improperly, and the attack exploits this design failure. This paper describes the attack, how we implemented it, and some optimizations to make the attack more efficient. We conclude that 802.11 WEP is totally insecure, and we provide some recommendations.
    stolen from here
    more detail here

    more links here.....must I go on ?
     
    Last edited: Aug 3, 2002
  15. Foxster

    Foxster Member

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    Ok, fair point, though for a home setup, WEP should be more than sufficient and WEP2 better still. In a small home setup, there isn't usually much at stake other than a particularly high internet bill if you have a cable setup and someone is leeching off your network. Then on top of that, if you assign static IP addresses and disallow access to any other IP, your wireless setup should be pretty secure. As said earlier, if someone really wants in, then you're pretty powerless to stop them but at least you can make it hard for those who don't really know what they're doing. I guess, more to the point, encryption is a good security measure as long as you don't rely on it as the only security measure since nothing is impervious to attack. It's a great first line of defence against amateur net stumblers.
     
  16. x0nt

    x0nt Member

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    Exactly :)

    However if you need the bandwidth and your hardware cant cope with wep (as a result wep decreases bandwidth), just secure your other machines and give out static ip's. Another option is to stop the ap sending out a signal saying "here i am, connect to me". I forget the technical term for it.

    Otherwise just whack WEP on and it should deter 99% of those intending to get onto your network.
     
  17. Foxster

    Foxster Member

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    Very true, though there are some systems that don't adhere strictly to the standards and offer higher bandwidth, but I'd be wary of such hardware if compatibility is going to be a problem.

    I think that for anyone wanting to use wireless, it's worth doing a little research or being involved in some discussion on the topic so they are aware of the dangers with the open nature of the system. I guess it wouldn't hurt to learn a little about network administration either since you will want to know how to tighten up the security a little.

    On a side note, I think this thread is going well so far with plenty of discussion on a variety of points and since wireless is just starting to take off it's a good time for discussion also.

    And for anyone in Brisbane, there's a site called Brismesh that covers wireless activity in the local area. There is a wealth of detail available on this site with regard to local nodes, line of site connection between specified points, etc. Looks like these guys are trying to set up a wireless community in the area and it looks like an interesting idea.

    I also have some links to sites that have details on how to construct your own wireless antenna from a simple tin can antenna to a high gain 2.4GHz helical antenna. Just in case anyone was interested ;)

    I've been looking into this sort of stuff for a while :D
     
  18. Shado

    Shado Member

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    I'm pretty sure ad-hoc can be used for more than 2 pcs but you can't have an A>B>C type network, if A can't directly talk to C, B won't pass it through. With an access point it will pass all communication through it.
     
  19. OP
    OP
    Stanza

    Stanza Member

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    Sorry guys and gals, had a whole heap of responses typed in read to post.........browser crashed and BANG all that typing is gone........ARGH.

    Will type it all again when I get time, gota go to bed early off to get more galaxy antennas tomorrow
     
  20. x0nt

    x0nt Member

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    Awwww I want one :(

    Everyone in my area has the weird black round antennas, I could probably get over 20 in one day but I heard these cant be used :(
     
    Last edited: Aug 4, 2002

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