Nick Rout wrote, On 02/03/10 21:49:
I have run a couple of cat5e cables and I am trying to terminate them,
unsuccessfully at present.
What kind of cable? Solid core or stranded? Is it fixed in the wall or
is it running around the floor?
Will a cable tester help me? I suspect that each time I put a plug on
the end one or more of the wires is in the wrong place, or not quite
long enough to make the connection. Coupled with this I am only 90%
sure which cable end is which at the switch end (ie the centre of the
star), having failed to mark them.
Easy way is to use a tone source. I have one.
Is there some sort of cable tester that can, eg, tell me what wires
are right and what are wrong, and which end of the cable is wired
wrong?
Yes and no... Cable continuity testers are $20 to $100ish and they step
across 8 or 9 pins sequentially, putting a voltage on the other wires to
complete the circuit.
More expensive boxes are called scanners and cost thousands - they can
do things like testing all OSI layers (ie speak a full smtp session with
a remote host) as well as testing actual voltages, cable lengths, noise
factors, etc.
We had an issue with an IBM x3350 server... loverly 1RU box with a dual
core CPU, lightpath, raid, dual PSUs etc etc. Worth around $7k. It
would randomly drop HD0, and possibly lock up and die. Once it
completely lost both ethernet interfaces on a dual port PCIe NIC.
It is dual UPSed up the wazoo.
We replaced the IBM motherboard, drives three times, cables, backplane,
raid controller, ethernet card, riser board etc all to no avail.
Turns out that there was a POE injector up the cable, and it was putting
out-of-spec voltages down the ethernet straight into the firewall.
Putting a fuse in place (actually a cheapie 5 port ethernet switch as a
sacrificial protection) seems to have cured the problem.
So a voltage-reading scanner scope would have found that much quicker.
The previous box in the same position was an IBM x306, which died in a
similar but more permanent way.
http://www.atecorp.com/equipment/fluke/675.asp
That one even measures token ring round-trip time and corrupt packet
generation. Its worth around $25k.
And, heres the hit, can someone in ChCh lend me one?
Of course!
--
Craig Falconer
