Terminating cat5e cable

My home network has been wired up and all that's left is the installation and termination of the cat5e cabling to the keystone RJ45 sockets and to the patch panel at the other end.

I've done a trial run of this using a length of the solid-core cat5e used; I've connected one end to the RJ45 socket according to the colour-coded terminals (I believe it uses T568B coding) and the other end to the patch panel (again using T658B). When testing with a signal tester with one end plugged into the RJ45 socket and the other into the patch panel, I see that pins 1 and 2 are reversed, i.e. one end of the LAN tester shows pin one active whilst the other end shows pin 2 and vice-versa. I'm actually connected to my router via this setup so I know it works, but is the "crossover" of pins 1 and 2 due to the patch leads used to connect to the patch panel and RJ45 socket?

http://2.bp.blogspot.com/_Vs6jmeNmJV0/SvQGCYAykPI/AA...

Crossover for connecting PC to PC usually. Straight Through for PC to router.

That would indicate one end is incorrect. Looking at the links, the socket info looks correct but no info for the patch panel bar what spec.

Make sure the leads you use from the socket/ PPanel are ok, have come across duff premade leads plenty of times.

Check that the RJ45 pins on the socket go to the correct IDC pins and similarly on the patch panel. Check that the numbers/colours align on both.

Make a very short patch panel to RJ45 connection and try 1>>1, 2>>2 &c using a standard DVM

You've probably done this already, but here's what I do,

- Get two short, straighthrough patch cables (50cm, 1m at most I use, so they fit in the case with the tester - no hunting for cables when you need 'em!)
- Test each patch cable using the tester, check you are getting straightthrough.
- Punchdown one wall socket, and one panel socket, and test that.

Maybe a rogue crossover cable used for testing?

In reply to a post by shtu:

Maybe a rogue crossover cable used for testing?

Would not be a crossover cable as further mismatches would be seen. Maybe a faulty cable where just 2 wires had swapped in assembly and not picked up in production test/

That is why I suggest checking the one socket to panel connection with a DMM/DVM

In reply to a post by Rockh:

That would indicate one end is incorrect. Looking at the links, the socket info looks correct but no info for the patch panel bar what spec.

For the patch panel, using T568B, I've connected as:
Pin 5: white-blue
Pin 4: blue
Pin 1: white-orange
Pin 2: orange
Pin 3: white-green
Pin 6: green
Pin 7: white-borwn
Pin 8: brown

As I mentioned, my lab setup works fine, I'm actually connected using the RJ45 keystone and the patch panel linked by a ~1m length of cat5e solid core. I'll test the patch leads used from the PC to socket and patch panel to switch

Pin out is correct ... definately points to a dodgy patch lead - assuming the IDC numbering on the patch panel is correct.

Feeling rather stupid after I re-checked the patch panel punchdowns and noticed that I has pins 1 and 2 reversed.

But even so, the connection still worked and I could connect to the internet, despite the polarity of the transmit lines being reversed; could that be down to my Netgear switch doing something clever?

Oops !

I think most (all?) consumer kit these days it auto-sensing, the manufacturers don't trust the public to know whether to use a straight or crossover cable.

Which makes life much easier for all of us

But a half straight / half cross over ... an interesting variant! Is there such a thing as a "bi-" cable?

But as it is Tx+ & TX- it should not be too much of a problem.

In reply to a post by MHC:

But a half straight / half cross over ... an interesting variant! Is there such a thing as a "bi-" cable?

A good question

Must admit I'd always assumed that Ethernet input stages were differential (for best CMRR) and could handle pretty much anything vaguely legal that you threw at them, including inverted binary due to a half crossover... sounds like, purely by accident, I may have been right!

did you get them wrong on both ends? if so then it cancels the problem out

In reply to a post by Pipexer:

did you get them wrong on both ends? if so then it cancels the problem out

No, just at the patch panel end