Cat5e Network behaving strangely

d4rk15000

Reputable
May 11, 2017
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Hey everyone,

today I have finally found the time to set up a new access point in addition to my Router for extended WLAN+LAN Switch capabilities.

In order to set it up I had to cut through my existing ethernet cat 5e wall socket installation. And whilst doing this I have found out something... odd or rather something I can not yet explain.

The wall socket has a color table on the inside, which corresponds to a normal A/B type cat 5e patch cable. Upon closer inspection I noticed that I funked up the setup when I did it a few years ago. I.e. I had switched the green and orange pair and created a crossover-setup by doing this. Since Gigabit Ethernet should be able to allocate the pairs as needed, I hadn't noticed any problems in the last few years. But what has caught my attention was that I had initially switched each colored cable with it's white counterpart - by that I mean that I have wired Brown to Brown-White, Orange to Orange-White, ... instead of going Brown to Brown, Orange to Orange, etc.

Since this seemed rather odd I have decided to clean the wall socket up a bit. I connected the cables according to the color chart and got no real connection at all. The connected devices realized they were in some kind of wired network but couldn't make any sense of it - so no connectivity.

Then I tried to switch the green and orange pair, re-establishing the crossover-setup I had for so many years - and bang, complete connectivity. But here's where it gets interesting. I went to a site to measure my connection speed. I was getting a rather okay 1.08mb/s DL and 110kb/s UL.

But since I was curious why I switched the colored and respective white cables I went on and rewired the wall socket again. This time I went with the crossover setup with the switched colors. Again about 1.09mb/s DL and roughly 108kb/s UL.


And here's the part I don't really understand: I then created a normal patch setup with switched color lines. And boom, I get 1.5mb/s DL and about 240kb/s UL.


It doesn't matter whether I plug the cables into my currently-in-use router, an AVM Fritzbox or an Arcadyan 803B Easybox. Neither does it matter which devices I use on the network. PS4, Windows Desktop, Linux Mint Laptop, ...
Each and every time I get the same results:

- Normal Patch setup: No network connectivity
- Normal Crossover Setup: Gigabit Ethernet connection established, ~1.10mb/s down- and ~110kb/s upload
- Crossover Inverted Colors: Same as above
- Patch Inverted Colors: Gigabit Ethernet connection established, ~1.5mb/s down- and ~240kb/s upload.



Does anybody here has at least a clue what is going on with my setup? I mean, I'm totally okay with the extra speed, it is just that I want to comprehend/understand it.


Thanks a lot for your help <3



TL;DR: Network is funky, non-standard cable setup gives me abnormal speeds, someone please explain.
 
Solution
The devil is in the details....

My suggestion would be to diagram the 568 pin to pin wiring from one end to the other.

Trust that you have a router with LAN port patch cables going to a patch panel. All those patch cables should be identical 568A or 568B. And also trust that the patch panel is feeding the various ethernet wall ports within your house likewise using 568 A or 568 B

Starting from the patch panel to each wall outlet. The wiring and pins must be likewise be consistent: all either 568 A or 568 B.

No crossover cables. No longer necessary unless you have some older devices.

And be careful about the plugs and ports. It is all to easy to reverse the pins if you are not consistent how you orient the plugs and ports...
The devil is in the details....

My suggestion would be to diagram the 568 pin to pin wiring from one end to the other.

Trust that you have a router with LAN port patch cables going to a patch panel. All those patch cables should be identical 568A or 568B. And also trust that the patch panel is feeding the various ethernet wall ports within your house likewise using 568 A or 568 B

Starting from the patch panel to each wall outlet. The wiring and pins must be likewise be consistent: all either 568 A or 568 B.

No crossover cables. No longer necessary unless you have some older devices.

And be careful about the plugs and ports. It is all to easy to reverse the pins if you are not consistent how you orient the plugs and ports.

If you drill into the wiring pin and punchdown details then you will probably be able to recognize what has transpired.

It can all get rather "funny" at times. E.g., two wrongs can make a right.....

Plus, the wires may be correct but a bad or marginal punchdown or crimp will make performance suffer. And remember that the speed tests are subject to any number of variables. Many of which are not within your perview.

I.e., "extra speed" is really the performance you should have. The lower value thus representing some degraded performance.



 
Solution

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