Ask LH: Are My Long Network Cables Slowing Me Down?

Ask LH: Are My Long Network Cables Slowing Me Down?

Hey Lifehacker, Cable question: Currently I am using a 7-foot Cat 5e cable from the router to the ethernet wall jack in the bedroom upstairs. I want to use a 100-foot cord. I need to run it out the upstairs window, across the porch roof and down into the window on the main floor into my office. We lease, so drilling holes and feeding it downstairs is not an option. The room where it is now is directly above the room it needs to feed into. What I’m wondering is: does longer cable equal slower speed? Thanks, Cable Confusion

Cabling picture from Shutterstock

Dear CC

When it comes to signal transfer and cable lengths there are lots of factors in play. For example, you need to consider how well insulated the cable is, the nature of the installation (if the cable is exposed to the elements then keeping it in conduits for protection will ensure that it performs well for as long as possible) and the quality of the terminations at the cable ends.

Cat5e cabling is designed to run at lengths of up to 100m – about three times the length you need so you’re not likely to hit any limitations in the cable.

Logic dictates that the longer the cable the longer it will take data to move. But at the length you’re talking about we’d be very surprised if the cable length was going to impact performance. We’ve run cables much longer than you’re describing as part of office installations and cable length is never a significant factor in performance.

Just make sure it’s a good quality cable and that the plugs on the ends are installed correctly, As the cable will be running outside, protect it as well as you can. Run it in a sealed conduit if possible so that the cable doesn’t perish when exposed to the elements.

Cheers Lifehacker

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  • Maybe the article should also point out that running a Cat 5 cable across the porch roof isn’t a very smart thing to do and has more influence than the length of the cable.

  • Prolonged exposure to the elements tends to make plastics… brittle.
    Brittle cables get cracks, which allow moisture in, which effects the properties of the cable.

    Unless you get cable rated for outdoors (TV co-axial) be prepared for degraded performance over time. When your lease runs out, don’t bother keeping the cable.

  • The signal carried by electricity travels at a large fraction of the speed of light (between 0.66c and 0.96c) so over 100 feet (30 metres) the added latency would be approx. 30/(300000000*0.66) = 0.15 microseconds.

    The issues are, as others have said, that exposure to weather will cause degradation in the cable. If you ask nicely your landlord may permit you to make the necessary internal alterations. In that case you will need to do a professional job (secured wall plates).

    As for cat5e vs. cat6, cat6 cable is significantly stiffer and so a bit harder to run around tight corners. Both will carry gigabit speeds over their rated lengths. I normally wouldn’t worry about cat6 unless I’m anticipating a major network upgrade (i.e. 10Gbps) *or* hostile conditions (such as running the cable over a porch roof).

  • The easiest way to protect Ethernet cable for outdoor runs, is to simply shove it inside some garden hose. It stops the Ethernet cable dying under the sun’s UV, and you don’t need to worry about sharp edges destroying the cable.
    I don’t really understand Temujin’s post above – “running a Cat 5 cable across the porch roof isn’t a very smart thing to do”. It’s absolutely the smart thing to do if you want to get 1Gb data rates from A to B. There’s no Wireless or Powerline solution that will match the speed of a $20 network cable inside a $20 garden hose.

  • Might be worth mentioning that it’s illegal to run LAN cables out windows, through walls…
    Needs to be done by a licensed person.

    Won’t help this situation but it should be mentioned.

    • Putting permanent cable in a wall, with a wall plate, is supposed to be done by a person with an AUSTEL cabling licence. Primarily to ensure you comply with seperation [15cm?] from power cables, use white ducting [not orange, that’s for power]. Underground cables also have some fancy requirements.
      Running it out a window is like laying it on the floor – can be done by anyone.

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