Confusion about network ethernet length

Discussion in 'Computers' started by Matthew_V, Jun 2, 2005.

  1. Matthew_V

    Matthew_V Stunt Coordinator

    Mar 26, 2003
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    My father is planning on purchasing a laser printer that will be connected to a network via a wired connection.
    Because of space constraints, the place in his office where he plans to put the printer would require an ethernet cable of a length around 5feet to 15feet (That's a rough guess because the cable would be running underneath the desks and tables in the office).
    There is a wireless router with three ports that are still available for a wired connection, and this additional cabling would be connecting the printer directly to the router.

    Using google I found various websites that gave the consistent answer that the maximum length is 100 meters, but what confused me is this answer that I found on The bolded text is the specific part of the answer that confused me -- I do not understand what he was talking about.

    Thank you in advance
  2. ScottHH

    ScottHH Stunt Coordinator

    Oct 24, 2002
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    I think he's saying you could run a cable up 90m, and then have 5m horizontal runs on both the bottom and the top. I wouldn't worry about it. I have run 100 ft. of cat-5 cable in a basement. I've also run up from the basement through the first and second floors, across the attic into a second floor bedroom. I have not had any problems. 15ft is not a problem. Make sure you don't put any kinks in the cable or put it where it can be walked on.

    Just remember that you need a network ready printer or a print server.
  3. Joseph DeMartino

    Joseph DeMartino Lead Actor

    Jun 30, 1997
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    Real Name:
    Joseph DeMartino
    They're just pointing out that the 100 meters total includes both the in-wall run and the patch cables at either end.

    Typical office installation: You have an equipment room. You have a switch or a hub. That is connected by a patch cable (call it cable A) to what is called a patch panel. This is a "box" that has, say, 25 or 50 RJ-45 jacks on the front, and room for you to punch-down the individual wires from 25 to 50 category-5 or -6 cables on the back. Those cables, in turn, are fed (usually by conduit) into the wall, and then they are routed to individual offices, and individual wall jacks within each office. Call the cable that runs from the patch panel to a given jack cable "B". Finally you have cable "C", which is the patch panel that runs from a laser printer or PC to the wall jack in that office. The three segments are what connects that particular printer to the hub or switch, and therefore to the rest of the network. The example you quote is pointing out that in calculating the 100 meter limit, you have to include all three segments. If you have 5 meters from hub to patch panel, and 90 meters from patch panel to wall jack, you can't put your laser printer 10 or 20 meters from the wall jack - you'll be over the limit. Some people misunderstand the 100 meter limit to mean that they can create a run from a wall jack for 100 meters to a network device. Doesn't work that way. You need to take into account the total run.

    In the example above if we change the assumptions and posit that the in-wall segment is only 50 meters, you can put the printer further away from the wall jack.

    None of this will really apply in your situation, but that's what they're talking about.



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