Ethernet cabling interference


I have two Mikrotik wifi access points connected via Cat6 cabling and powered up using passif PoE injectors (cabling length: 20m and 30m)

At both ends I have Cat6 sockets ends (568B) with short Ethernet patch cables
I can't get the devices at either end to negotiate a Gigabit or Fast Ethernet connection (and yes, devices at both ends are Gigabit capable)

At the moment the best I get is 10 Mbps and that doesn't even seem to be stable: packet losses from time to time

I checked my cabling using a GREENLEE TEXTRON-NC-500 Netcat PRO 2 and all seems tip top

The cat6 F/UTP cable sections pass through the ceiling plenum, and are enclosed within convoluted sleeving from one end to the other

I have another set of cables that follow a different path, along the foot of the wall) and have no issues whatsoever (1 Gbps)

The ceiling plenum has A/C ducts, IR Infrared Motion Sensor Switches, and the lighting systems of course.  

I can only assume that something is causing interference, but this is the first time I come across such a phenomenon.

Tomorrow I will plug the APs straight into the switch to see how they react; if all is well then it will reaffirm my assumption that interference is the trouble maker here

Can anyone confirm or contradict my assumptions ?

Yann ShukorOwnerAsked:
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Martin MillerCTOCommented:
Not 100% conclusive, but, I think you are on the right track, please update again when you resolve the next level validation.

Powerline and other HVAC electrical will have more impact on the signal as it weakens with longer cabling, e.g. impacting Signal/Noise ratio.

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David Johnson, CD, MVPOwnerCommented:
Are you using shielded solid vs stranded ethernet cables?
If you can afford it or do a lot of cabling get a fluke network tester either buy or rent
Olgierd UngehojerSenior Network AdministratorCommented:
There are 2 kinds PoE injectors for Mikrotik, one works for 100Mps second up to 1Gbps.
First check tat you have once what supports 1Gbps.
Check cable as well, you can have broken one, I know that you checked it but it can be socket broken as well.

One more thin is to check interface configuration on Mikrotik - you may have some wronk settings ther, like half duplex etc.
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If the ceiling plenum contains fluorescent light fittings, make sure that any network cables are as far away from them as possible, as such fittings emit quite a bit of RFI.
Out of interest, is the cabling at floor level  also Cat6, or Cat5e?
Yann ShukorOwnerAuthor Commented:
Yes, Perarduaadastra, cable doesn't run directly over fluorescent lighting systems
Yes, we used the cat6 cabling along the floor level.
Yann ShukorOwnerAuthor Commented:
Well the issue was two fold, the RJ45 sockets seemed a little under par and one of the access points was faulty
Thanks for your help
Martin MillerCTOCommented:
Yann, Glad you got this resolved and thank you for the points !

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