Post by Roy
Anyone recommend a solution to a long Ethernet cable (600 feet or os)?
I mentioned a StarTech ADSL convertor earlier but was wondering about
any other solutions out there
How fast do you want to go, or rather what's the lowest connection
speed you can tolerate? Also do you need full duplex (FDX) or can you
live with half duplex (HDX)?
I've done 900ft over CAT5e at 10 Mbits/sec. I don't recall if it was
HDX or FDX, but I think it was HDX. The only trick was to use an
ethernet switch at both ends, instead of a LAN card. One end was a
"managed" switch, which allowed me to set the speed/protocol, which
was necessary to force the speed down to 10 mbits/sec and force it to
FDX or HDX. It also allowed me to monitor the performance using SNMP.
100Mbits/sec HDX worked, but SNMP monitoring over several days showed
a few errors, which I deemed to be excessive. It was installed and up
for about 10 years(?), with no obvious problems.
One would assume that all ethernet ports have the same tx drive power
and rx sensitivity, but that apparently is not the case. You may need
to pick and choose your endpoint devices.
About 5 years ago, I wired a second 10baseT FDX circuit into the same
CAT5e cable bundle. I was worried about NEXT (near end crosstalk) and
PSNEXT (Power Sum NEXT) which I'm sure were well out of spec. Sure
enough, even at 10baseT speeds, I started to see errors. Since the
data on both pairs were non-orthogonal, that was no surprise. So, I
dragged out a 1000ft roll of CAT6 and tried the same tests in my
palatial office. No crosstalk was observed. CAT7 should have been
Replacing the CAT5e with CAT6 or CAT7 or adding another cable would
have been easy enough, but the decision makers opted for someone elses
fiber optic solution. That was admittedly the right choice, even
though it cost far more than one additional cable. However, the
certified cable installer scrambled the instructions and failed to
remove the CAT5e cable. Oh well.
At this time, the original system is still running on the original 15
year old CAT5e cable, while the added circuit is running on a fiber to
100baseT converter, with the 2nd line fiber converter unused. It
seems that when running both fiber circuits at the same time, there's
some interaction that causes problems. I have no idea what that might
be and since it's NOT my problem and since they don't want to pay me
to fix it, I have only some bad guesses as to what's wrong.
I've installed several other absurdly long CAT5e runs without
difficulties. As long as the speed is kept down to 10 Mbits/sec, it
seems to work. The key seems to be to carefully select the switches
at both ends. Grab a 1000ft roll of CAT5/6, crimp on some connectors,
and do some testing where you can see what's happening at both ends.
Also, there's quite a bit of garbage CAT5 on the market. I test the
rolls I buy and have found a few bad rolls this way.
600ft should be easy if you have decent cable and hardware.
Jeff Liebermann ***@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558