Coiling ethernet cable causes latency issues

tom_1989

tom_1989

tom_1989

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11 Jun 2014
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26
Hi everyone,

Just thought I share my experience. Yesterday, I installed a new CAT6 UTP 50 metre Ethernet cable (24 AWG, 100% copper). I had previously used the cheap 30 metre CAT 5E cables off ebay and never had any real problems but since I was going to all the effort I thought I would go for something of higher quality.

Anyway, after installing it I had 10 metres excess so I decided to coil it tightly using tie raps. My download speed was still over 100 Mbps. But when I started to surf the web and watch youtube videos I started to experience huge amounts of lag.

After I uncoiled the excess cable, the lag issues have disappeared (as far I know). But most of the info from forums say that coiling an ethernet cable won't cause any interference problems, even is the cable is UTP. But unless my situation is just a coincidence, then it surely does, so I thought I would share it with others.
 
I've been using a coiled 15 metre Cat5e UTP cable for almost a decade. Only about 5 metres uncoiled. Used with many devices over the years. Never had any such problems.

My cable is coiled in a figure of "8" rather than a circle.

Maybe the coil itself was near a source of interference? half a metre passing through a bad zone is nothing compared to a whole 10m coil in it.

Cables also have a natural coil. If you uncoil and recoil you need to make sure you're twisting the cable in the right ways.

Cat6 also has stricter bend radius requirements.
 
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I've also coiled Cat5e cable and never noticed anything untoward, but my coil would have been one or two turns of a metre each. A tightly coiled 10M length of cable will add inductance to the cable and allow it to receive interference that it would normally reject.

Just relax the coil significantly to tidy your cable mess, or chop the end off and re-terminate.
 
If you must coil up network cable, try to keep as far away from electrical outlets and other electrical devices.
For example, coil up in between the PC and router/modem rather than at each end next to the PC or router/modem.

Make sure no other cables (electrical/USB/DVI/HDMI etc) are in contact with the network cable as well.
You can always try getting some ferrite core snap on clamps for the cable to minimize EMI interference
 
UPDATE

The lag is still reduced. Prior to uncoiling the cable, there would be a 4-6 second delay in a web page loading (if it loaded at all). Now there's just a split second delay.

The excess of 10 metres was coiled into about 10-11 circular loops and bond tightly together. All I have done now is run the cable back and forth a few times above 3 double wardrobes so that the cable is not touching each-other. Also, there was defiently no other electrical interference near the coil.

I did try to tightly coil a 3 metre cat 5e cable but found no interference issues. This means that the stricter bend radius requirements of the CAT6 is the issue or maybe there is some sort of damage to the cable. Anyway, I'm just glad it working after spending all Saturday fitting it :)
 
do a
ping -t yourRouterIP


Then watch it as you make coils..

I'd just put the correct length in
 
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