Abnormal cross-pair coupling

[mhoppes]

What does this error actually mean?





Pair 1 Status (Pins 1,2) (Pos) (Orange)
Open


Pair 2 Status (Pins 3,6) (Neg) (Green)
Abnormal cross-pair coupling, pair 3


Pair 3 Status (Pins 4,5) (Pos) (Blue)
Short


Pair 4 Status (Pins 7,8) (Neg) (Brown)
Abnormal termination

[sirhc]

So you fail to disclose what the conditions are.

Is this a report on a port with nothing plugged into it?
- If so then this port is damaged, RMA the unit.

Is this a report on a port with just a cable with no device on the end of it?
- Possible bad crimp ends or bad cable.
- Port is damaged and the cable which could be fine is not the cause.

Is this a report with a cable and a device, if so what device?

Is this a report with a cable and an Ethernet Surge Suppressor and a device?

Below in red Pair 2 is the one that most concerns me which is a cross pair short?
Pair 1 Status (Pins 1,2) (Pos) (Orange) - Open
Pair 2 Status (Pins 3,6) (Neg) (Green) - Abnormal cross-pair coupling, pair 3
Pair 3 Status (Pins 4,5) (Pos) (Blue) - Short
Pair 4 Status (Pins 7,8) (Neg) (Brown) - Abnormal termination

To determine if the port is damaged simply try the cable in another port and then do the cable diagnostics (no POE).

Some devices report weird when unpowered but I would proceed with caution.
Some Ethernet Suppressors cause weird reports but I would proceed with caution.

Always best to pre-test with the factory POE brick first then insure the POE brick polarity PINOUT matches ours as detailed in this thread HERE.

If a brand or device not confirmed compatible with Netonix in the compatible list thread HERE I would read this post HERE and proceed with caution but this post also details how to proceed and test before applying POE power.

All the information you need and how to proceed is available on the forums and are simple tests people can perform taking caution not to simply apply POE power and throw caution to the wind.

[mhoppes]

The only part I'm concerned about is the error you highlighted (thus why it was in the subject line).

With the radio turned off in PoE the cable tests fine. With the radio on I get the cross-short and see all kinds of errors and negotiation problems on the port. There is no surge arrestor.

[sirhc]

The only part I'm concerned about is the error you highlighted (thus why it was in the subject line).

With the radio turned off in PoE the cable tests fine. With the radio on I get the cross-short and see all kinds of errors and negotiation problems on the port. There is no surge arrestor.

More info needed and confirmed:
- What type of radio or device is this?

- Your saying the switch powers the device then reports these errors while powered?


If the switch powers the device but you get weird errors I would do the following:

Try a differnt switch port and see if the issue follows the cable/radio;
- If fine on other port then you have a damaged switch port
- If problem follows cable/ends/radio then you know the issues is with the cable, ends, or radio/device Ethernet port.

If the issue is down to the cable/ends/radio then you need to narrow down further, I would do in this order but up to you;
- Swap radio/device
- Re-crimp ends
- Replace cable

I have come across several radios being a WISP over the years that had a damaged Ethernet port. They are just as susceptible to damage as our switch ports especially from ground current. The one that comes to mind the most was an AF24 on Hillcrest water Tank in Leola. Turned out the Ethernet PHY was damaged in the radio but we only discovered this after we re-crimped the ends, then ran a new cable, and lastly swapped out the radio. We were able to replace the PHY on the board and the Ethernet Transformer for good measure and the problem went away and is currently in service to this day on another tower. Since you may not be able to do these types of repairs you would need to RMA the radio to the manufacturer.

Being a WISP requires one to be sort of a detective and use common sense diagnostic skills to narrow it down to determine what is at fault.

With all the suggestions I have provided you it should be easy to narrow it down to the exact device causing this issue. I have detailed this exact same diagnostic scenario/procedure many times on this forums and previously on the UBNT forums years ago.

This is not a hard issue to narrow down but my crystal ball is no better than yours or anyone else's so I would do exactly the same as what I expressed above and would figure it out.