OT IT Pros- wireless technology question

Discussion in 'OT Technology' started by Up All Night, Aug 23, 2007.

  1. Up All Night

    Up All Night I might sleep all day

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    I'm trying to get a bandwidth cap raised and and need this hypothetical situation answered:

    I'll simplify this as much as possible: Say you've got a business with an OC3 line that connects it to the internet and provides, I don't know, 120 MBPS of bandwidth. That business has a Wireless G router with 1 computer connected to it. That person can, theoretically (yes, i know it wouldn't even be close in practice) get 54MBPS of that bandwidth, maxing out the wireless connection.

    Now say another computer connects to that wireless network. Is the 54 MBPS limitation of the wireless G router split among both computers, meaning that each can only use a theoretical max of 27 MBPS of the 120 MBPS bandwidth? Or, can each computer connected to the router use 54 MBPS of bandwidth, for a total of 108 of the 120 MBPS?
     
  2. P07r0457

    P07r0457 New Member

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    wireless bandwidth is SHARED
     
  3. Sexual Vanilla

    Sexual Vanilla New Member

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    The 54 Mbps refers to the maximum theoretical throughput on that specific channel. In other words, 54 Mbps is the maximum transmission rate, regardless of the number of nodes using it.

    Because of the very nature of wireless transmission (and the protocols used within it), each node would be transmitting separately anyway, as more than one node transmitting at a time would result in a garbled signal (collision) that the router would not understand.
     
  4. P07r0457

    P07r0457 New Member

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    um, no. your post implies that each host would see 54mbps and that is incorrect. due to time-division, the available bandwidth decreases as nodes increase.
     
  5. Up All Night

    Up All Night I might sleep all day

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    I see. And wired bandwidth isn't?
     
  6. Kewlb

    Kewlb New Member

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    This depends on the type of device used and the backplane speed of said device.

    You can also implement QoS policies (marking and shaping would work in your case) to handle bandwidth concerns.
     
  7. P07r0457

    P07r0457 New Member

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    not necessarily.


    Take this scenario.... FOUR clients connected to a wireless network. Clients 1 and 3 talk to each other and 2 and 4 talk to each other. They all share a portion of time on the wireless network talking, so your maximum bandwidth is 54mbps/4 ~ 13.5mbps per client (max theoretical, not practical bandwidth -- which would be less, I'd say around 7Mbps).

    Take the same four clients with same demands and put them onto a standard 100Mbps switch and each connection would get a 100mpbs full-duplex connection. The switch will allow two machines to talk at the same time. If both machines are uploading to the others, then you would get approximately 400Mbps of max theoretical bandwidth, with a more practical appreciable limit around 300mbps -- a definite improvement over wireless, would you not agree?)
     
  8. Kewlb

    Kewlb New Member

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    still just 200Mbps per machine, if this is what you meant you certainly did not state it clearly. This is also 100Mbps both ways ie: 100Mbps upstream and 100Mbps downstream just to clarify for the user.

    this also still depends on the backplane speed of the switch being used. A lot of these home DSL/Cable routers do not have the backplane speed to support 4 stations at max bandwidth, hell most of them can not support 3 stations going at max port speed, but what do you expect for <= $100
     
  9. P07r0457

    P07r0457 New Member

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    given a backplane to support it, 4 clients could saturate 400mbps. Given 20% overhead (very high) they are approximately 300Mbps;
     

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