Networking Question

Discussion in 'Mac Accessories' started by dsnort, Feb 2, 2008.

  1. dsnort macrumors 68000


    Jan 28, 2006
    In persona non grata
    Sorry if this is a stupid question, but I know very little about wireless networking.

    I have four comps in my house working on a wireless network utilizing an Apple Airport Extreme base station. All but one of these machines has wireless N, and the one that doesn't have wireless N is hooked to the base station via ethernet.

    I recently bought a vintage iBook Clamshell with a wireless B airport card installed, ( purchased, but it hasn't arrived yet). If I attempt to connect the Clamshell to my wireless network, is it going to pull my entire wireless network down to "B" speed?

    Also, I have seen where certain older wireless cards don't support WPA2 encryption. Is there a way to rectify that?

    Thanks for the help!
  2. Shredster00 macrumors newbie

    Jan 21, 2008
    Speed and range will be less if an 802.11a/b/g device joins the network, however it will not be all the way down to "b" speed.

    As far as the WPA2 goes, I'm not sure if thats possible or not.
  3. Killerbob macrumors 6502a

    Jan 25, 2008
  4. macleod199 macrumors 6502

    Mar 10, 2007
    WPA was apparently intentionally designed to only require the same hardware accelerated operations as WEP, so it could be done as a software/firmware upgrade. However, WPA2 was designed without this constraint, so it's less likely to be upgradeable.

    Regarding the speed question, as a VERY rough analogy, you can consider there being a certain number of 'slots' available to transmit every second (depending on the protocol these could be time, frequency, code or spatially divided, or some combination of these). A device using the fastest 802.11n mode is able to create far more slots per second than a g or b device. So whenever a b device is transmitting in one of its (relatively) large slots, it knocks out a whole lot more slots from the perspective of the 'n' devices.

    Say the 'n' devices are using 16 slots for every 1 of the 'b' device. If two 'n' devices have 6 slots of data to transmit each, they can each do that in the equivalent of one 'b' slot, with room to spare and without tripping on each other. If the 'b' device grabs its slot, however, they both have to wait, and the whole network will briefly switch back to using the old, larger slots.

    The new routers are probably pretty good at switching between the old and new modes pretty quick... as they have to degrade to using 'larger slots' anyway when 'n' devices are getting out of range (this is why your connection slows down before it drops out). But depending on the quality of all the devices on there, it could cause problems.

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