Any LAN wiring cable experts out here?
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Any LAN wiring cable experts out here?
Hello!
I am stuck on a more hands-on project that wants to turn me into an axe murderer, part II. Instead of yelling at clouds again, irritating my neighbo (u) rs ("OMG, he flies airplanes"), I've decided to post on pprune. Most feedback on here had been excellent!
I have laid a CAT 6 cable (~20m) in my basement to connect a mini switch (Unify Flex) to the main unit (UI Dream Machine SE). I want to connect security cameras and maybe even an exterior AP via the UI Flex. I crimped the LAN cable (T-568B) and it tested OK. Connected it and ... no data. The UI Flex powers up, even powers one of the security cameras, but no data transfer between the flex and the DM. I disconnected everything, tested the cable again (no faults), even tested the ports on each unit with a different cable and everything checks OK.
Any ideas? I am confused why the LAN tester checks OK, but no data transfer occurs. Should I re-crimp?
7 7 7 7
I am stuck on a more hands-on project that wants to turn me into an axe murderer, part II. Instead of yelling at clouds again, irritating my neighbo (u) rs ("OMG, he flies airplanes"), I've decided to post on pprune. Most feedback on here had been excellent!
I have laid a CAT 6 cable (~20m) in my basement to connect a mini switch (Unify Flex) to the main unit (UI Dream Machine SE). I want to connect security cameras and maybe even an exterior AP via the UI Flex. I crimped the LAN cable (T-568B) and it tested OK. Connected it and ... no data. The UI Flex powers up, even powers one of the security cameras, but no data transfer between the flex and the DM. I disconnected everything, tested the cable again (no faults), even tested the ports on each unit with a different cable and everything checks OK.
Any ideas? I am confused why the LAN tester checks OK, but no data transfer occurs. Should I re-crimp?
7 7 7 7
Have you checked existing cable that you know works?
Have you checked for pin to pin continuity? Have you checked that no pin is shorted to any other? If neither of those fault conditions is present I see no reason to re-crimp.
Isn't the biggest problem with Ethernet that a straight cable was used when cross-over was required ( and vice versa)?
Isn't the biggest problem with Ethernet that a straight cable was used when cross-over was required ( and vice versa)?
Have you checked for pin to pin continuity? Have you checked that no pin is shorted to any other? If neither of those fault conditions is present I see no reason to re-crimp.
Isn't the biggest problem with Ethernet that a straight cable was used when cross-over was required ( and vice versa)?
Isn't the biggest problem with Ethernet that a straight cable was used when cross-over was required ( and vice versa)?
In your shoes I would be looking to test your Ubiquiti kit with a known good cable and/or test your cable with some other devices. If you can connect two laptops together through it and they connect at 1000MB then your cable's good.
What sort of LAN tester do you have? Some [cheap] types are basically just a dc continuity/short-circuit tester. Just because a cable passes at dc that doesn't mean it will work at Ethernet speeds - particularly if you need GBit. A proper LAN tester will confirm 1GB speed and give you error rates etc.
If you've made the same wiring mistake at each end of the cable it will pass the continuity check but may fail as an Ethernet cable. The coloured pairs have different twist rates which are carefully designed to reduce crosstalk interference at high frequencies.
How experienced are you at crimping Ethernet cables. It took me a while before I reached an acceptable success rate, though my use of the cheapest crimp tool I could find didn't help.
Provided you've got plenty of connectors and spare length on the cable then it won't do any harm to have another go. Do one end first, try it, then do the other end. If nothing else it will be good practice
.Double check you've got pin 1 correct and all colours as they should be.
Is your cable suitable for the connector? If you have multistranded cable then I think that needs a different type of connector body, and is harder to work with. I've never used it myself.
Good Luck.
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Update:
I finally managed to find some of my zen and sanity to calmly look into my cabling issue. I ended up replacing the expensive outdoor-rated cable with a cheap one from Amazon and voila! it worked! I have no idea what caused the old cable to show ok with my cheap cable tested but causing issues when connected. It's the first time I ran into this issue, I had crimped various cables at my old house.
@netstruggler thank you for all your input. May I ask you what tester you use to test speeds? All I have previously done was connecting the ol' laptop and go to testmy.net
I finally managed to find some of my zen and sanity to calmly look into my cabling issue. I ended up replacing the expensive outdoor-rated cable with a cheap one from Amazon and voila! it worked! I have no idea what caused the old cable to show ok with my cheap cable tested but causing issues when connected. It's the first time I ran into this issue, I had crimped various cables at my old house.
@netstruggler thank you for all your input. May I ask you what tester you use to test speeds? All I have previously done was connecting the ol' laptop and go to testmy.net
Update:
I finally managed to find some of my zen and sanity to calmly look into my cabling issue. I ended up replacing the expensive outdoor-rated cable with a cheap one from Amazon and voila! it worked! I have no idea what caused the old cable to show ok with my cheap cable tested but causing issues when connected. It's the first time I ran into this issue, I had crimped various cables at my old house.
@netstruggler thank you for all your input. May I ask you what tester you use to test speeds? All I have previously done was connecting the ol' laptop and go to testmy.net
I finally managed to find some of my zen and sanity to calmly look into my cabling issue. I ended up replacing the expensive outdoor-rated cable with a cheap one from Amazon and voila! it worked! I have no idea what caused the old cable to show ok with my cheap cable tested but causing issues when connected. It's the first time I ran into this issue, I had crimped various cables at my old house.
@netstruggler thank you for all your input. May I ask you what tester you use to test speeds? All I have previously done was connecting the ol' laptop and go to testmy.net
We have a tester at work; it cost a few Łk but it's very useful. It'll tell you if you have a short or open circuit and how many meters away it is. We use it for testing twisted pair modem cables over several kilometers. On Ethernet links it will inject ethernet packets and report error-rates and so on. I'm working from home at the moment but so I can't remember the brand. I don't think it's this one but it's this sort of thing.
SignalTEK CT
I'm not generally allowed to borrow it for home use
I'm not surprised you had trouble with an expensive cable. They can be harder to work with and may need special connector components and a special crimp tool, as opposed to the stuff that's easily available from you-know-where.
At work, where we can, we buy ready made Ethernet cables, test them in the office and then pull them through. Not always possible though.
Glad you're up and running.
To test network installations for bad cabling or bad anything else I would run some traffic over it. There are a few ways to do it.
Copy some files. Tough to saturate the network since there are disk drives and the utterly horrible microsoft network file protocol (CIFS) getting in the way. Can be done with no special expertise. One way round this is to use ftp, say Filezilla client and server pair. This is a much more efficient protocol. You can copy some big files and do several at once (>1 thread).
Robocopy can copy multiple files at once generating more traffic. /MT. Default is 8 which with big files will be quite a bit of traffic.
A simple ping can generate a surprising amount of traffic if a number of copies and large packets are used.
start cmd /c ping 192.168.1.87 /l 64000 /n 10
To run 3 copies:-
FOR /L %y IN (0, 1, 3) DO start cmd /c ping 192.168.1.87 /l 64000 /n 10
You will learn to check carefully and test with a small number of instances once you have had to close 200 windows manually when it all goes wrong.
Look at psping - a microsoft tool.
https://learn.microsoft.com/en-us/sy...wnloads/psping
The real tool is ttcp, the MS version is NTttcp. Not so easy to use.
https://github.com/microsoft/ntttcp/releases/tag/v5.39
You can look at interface error counts with perfmon or
netstat -e.
There is also iperf but I am not so familiar with it.
Copy some files. Tough to saturate the network since there are disk drives and the utterly horrible microsoft network file protocol (CIFS) getting in the way. Can be done with no special expertise. One way round this is to use ftp, say Filezilla client and server pair. This is a much more efficient protocol. You can copy some big files and do several at once (>1 thread).
Robocopy can copy multiple files at once generating more traffic. /MT. Default is 8 which with big files will be quite a bit of traffic.
A simple ping can generate a surprising amount of traffic if a number of copies and large packets are used.
start cmd /c ping 192.168.1.87 /l 64000 /n 10
To run 3 copies:-
FOR /L %y IN (0, 1, 3) DO start cmd /c ping 192.168.1.87 /l 64000 /n 10
You will learn to check carefully and test with a small number of instances once you have had to close 200 windows manually when it all goes wrong.
Look at psping - a microsoft tool.
https://learn.microsoft.com/en-us/sy...wnloads/psping
The real tool is ttcp, the MS version is NTttcp. Not so easy to use.
https://github.com/microsoft/ntttcp/releases/tag/v5.39
You can look at interface error counts with perfmon or
netstat -e.
There is also iperf but I am not so familiar with it.
But the cheaper ones cannot detect getting the conductors between different twisted pairs mixed up. If continuity is OK, the power over Ethernet will work. But crosstalk between mixed up wire pairs will mess up the data.
I've got a cheap, no name continuity tester. But I keep a little chart of which pin pairs belong in each color coded twisted pair. And inspect the finished product by eye.
