[renzki]

well most discussions seem to suggest that 100 meters is the length limit for cat 5e cables... i tried installing about 300 meters of cat 5e and this happened...

there is no connection when i set the pc to 100mbps connection speed, but when i drop the speed to 10mbps half duplex, there is a good connection!!!

what could be the reason behind this???

[puntoMX]

The answer you already gave, it’s the speed limit. 10Mbps just use 4 pins and not 8 pins and so you can imagine that those 8 pins (read wires) make a lot more inference at a 10 times faster speed .

[renzki]

if that is the case, why did the 10mbps full duplex didnt work but the half-duplex setting worked when i tested it?... they both use the same number of wires right?

[puntoMX]

Yep, they do, but see full duplex (In and Out at the same time) as 20Mbps .

[renzki]

and i thought those electrons wouldnt have any problem travelling those wires at all...

[Zxian]

It's actually not the electrons that are moving in the wires...

We had an assignment in my Electomagnetism course where we calculated the velocity of the electrons in a typical telephone wire... turned out to be about 30um/s (um = 1/1000000 m, you do the conversion to imperial... ). It's the electomagnetic wave that travels quickly along the wire.

Just some food for thought.

[Bâshrat the Sneaky]

I agree with Zxian.

It has to do with signal interference and not high enough signal strength for such distances. If you could use more power on the cable, it might work just fine. Only you'd have to hack your NIC for that

[puntoMX]

****, I used the wrong word, "inference", it´s "interference" indeed... back to school to crank up my English

[Bâshrat the Sneaky]

puntoMX, on May 31 2005, 08:44 PM, said:

****, I used the wrong word, "inference", it´s "interference" indeed... back to school to crank up my English
<{POST_SNAPBACK}>

LOL


Didn't notice though

[renzki]

Bâshrat the Sneaky, on May 31 2005, 12:09 PM, said:

I agree with Zxian.

It has to do with signal interference and not high enough signal strength for such distances. If you could use more power on the cable, it might work just fine. Only you'd have to hack your NIC for that
<{POST_SNAPBACK}>

LOL! uve done that in the past havent u?

[Lost Soul]

just curious is there any way to boost this distance by like placing some kinds of signal blocks on the walls for every 100 meters

[Zxian]

@Lost Soul:

Yep, that's exactly how they do it out in the bush.

A friend of mine was working with a company last year that had a number of sensor systems placed out in the forest. They relayed the signals back to the base center using ethernet cables. They had to put relay stations every 200m or so (they designed their own ethernet controller circuits so they could boost the power) since they needed to transfer the data at 100Mbps Full Duplex.

The relay circuit itself is really simple actually, just a plain old amplifier will do, with the signal in on one side and the signal out on the other.

[Lost Soul]

thats a great ideal,, how much do the relays cost

[Zxian]

If you wanted to make one for yourself, you could make one for ~$15 all included. I'm not too sure about commercial though... probably the same price.

[Bâshrat the Sneaky]

I'd be amazed if the commercial price would be so low

If you also need to split up the network - which you probably don't have to - you could of course simply but switches in between... But I think you already knew that...

[Zxian]

Bâshrat the Sneaky, on May 31 2005, 09:18 PM, said:

I'd be amazed if the commercial price would be so low

If you also need to split up the network - which you probably don't have to - you could of course simply but switches in between... But I think you already knew that...
<{POST_SNAPBACK}>

Well, just imagine the cost of a 2 port switch/hub and you've bascially got what you need. I've seen some no-name 4 port hubs sell for $25 CAD (~17 Euros).