CAT5 cable

  • Thread starter Thread starter Pat
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Pat

Anyone know what is the maximum distance a cat5 cable will reach a computer
from a router?
I am having difficulty connecting a computer over a long distance, the light
on the router is light, so there is a connection.

Thanks Pat
 
Anyone know what is the maximum distance a cat5 cable will reach a computer
from a router?
Click to expand...

100M or 330 Feet is the maxium distance for a length of cat5, regardless of what
either end is connected to..

Regards,
Chris
 
Skeleton Man said:
100M or 330 Feet is the maxium distance for a length of cat5,
regardless of what
either end is connected to..
Click to expand...


If the device is active on each end then 100M is the max length for the
single stretch of CAT5 cable. However, if a passive hub is used, isn't
the total max length the total of the longest two lengths of cable
attached to that passive hub (i.e., the passive hub just looks like a
splice)? With a switch, router, gateway, bridge, or other active
device, it becomes an endpoint in measuring the length of a cable, but I
don't think passive hubs effect a change in length (so two 50M cables on
it would be your 100M max length).
 
You should not exceed 100 meters, or 330 feet with CAT5. If you want to go
farther, you need to have a repeater on it. An active switch or another
router should do the job for you.
 
If the device is active on each end then 100M is the max length for the
single stretch of CAT5 cable. However, if a passive hub is used, isn't
the total max length the total of the longest two lengths of cable
attached to that passive hub (i.e., the passive hub just looks like a
splice)? With a switch, router, gateway, bridge, or other active
device, it becomes an endpoint in measuring the length of a cable, but I
don't think passive hubs effect a change in length (so two 50M cables on
it would be your 100M max length).
Click to expand...


Quick note of clarification here - looks like you're saying that hubs
are "passive" devices while switches, routers, etc are "active".
That's not true, as the hubs that are used with Ethernet today are all
"active devices".

Just wanted to be sure you understood that in this case active vs
passive doesn't mean whether or not a device acts "intelligently" on a
signal (IE: Switch Vs Hub), but whether or not the device contains
electronics and "repeats/regenerates" the signal.

IOW, you could have a hub, then 100m of Cat 5, a hub, another 100m of
Cat 5, and another hub, and still be fine. The Hubs I mean in this
instance are anyone of the generic $15 4-port model you can find at
any computer store (LinkSys, NetGear, etc).

For more:

http://expertanswercenter.techtarget.com/eac/knowledgebaseAnswer/0,295199,sid63_gci974732,00.html


Once again, no flame inteneded.
 
In message <[email protected]>
mhaase-at-springmind.com said:
Quick note of clarification here - looks like you're saying that hubs
are "passive" devices while switches, routers, etc are "active".
That's not true, as the hubs that are used with Ethernet today are all
"active devices".
Click to expand...

However, hubs do not create separate collision domains, which is almost
important when considering maximum cable lengths across your network.
 
In message <[email protected]>


However, hubs do not create separate collision domains, which is almost
important when considering maximum cable lengths across your network.
Click to expand...


True. And another important point to consider. I was just clarifying
the active/passive distinction.

M
 
mhaase-at-springmind.com said:
True. And another important point to consider. I was just clarifying
the active/passive distinction.

M
Click to expand...


But wouldn't an active hub do cleanup and re-amplication of the signal
(and why it is called an active hub)? That would be an endpoint and,
like you said, you could have a 100M on one port and another 100M cable
on another. However, I was thinking about purely passive hubs where
there is no cleanup of noise (i.e., filtering) and no re-amplification
of the signal to compensate for attenuation, and those are where you
would have to just look at it like it was a wire splice. Yeah, I
realize that in the last 4 years that all hubs are active but we've got
piles of really old crappy stuff filling up the supply cabinets.
 
If you've built this cable yourself, do you know that it is built
correctly? Very carefully check the pinout. Incorrectly wired cables
will often light up the LEDs but not work.
 
But wouldn't an active hub do cleanup and re-amplication of the signal
(and why it is called an active hub)?
Click to expand...

Yup. That's why it's called "active". It has electronics that do the
Cleanup & reamplification.
That would be an endpoint and,
like you said, you could have a 100M on one port and another 100M cable
on another.
Click to expand...

Yes - I just didn't want folks thinking that it was the routing of a
signal based on MAC addresses (or based on anything else) that made a
device "active" vs "passive". It's (as you pointed out) the
amplification. Basically, if the device requires power to run, it's
gonna be active.
However, I was thinking about purely passive hubs where
there is no cleanup of noise (i.e., filtering) and no re-amplification
of the signal to compensate for attenuation, and those are where you
would have to just look at it like it was a wire splice. Yeah, I
realize that in the last 4 years that all hubs are active but we've got
piles of really old crappy stuff filling up the supply cabinets.
Click to expand...

Truthfully, I'm not sure that true "passive" hubs have been used with
Ethernet in a loooong time -- if ever. I think they were only used
with other protocols (somebody correct me if I'm wrong)

You are correct though, if a true "passive" hub were used, the
implication for length on CAT-5 would be the same as if there were a
splice. In fact, as I understand it, many "passive hubs" were
actually just punch down blocks.

M
 
Pat said:
Anyone know what is the maximum distance a cat5 cable will reach a computer
from a router?
I am having difficulty connecting a computer over a long distance, the light
on the router is light, so there is a connection.
Click to expand...

Hi Pat,

Others have provided some important discussion. One thing that has not
been mentioned, however, may be important. If you've built your own
cables, you have to be careful to match the strands in a paticular
order. Here is an applicable description:

http://www.ertyu.org/~steven_nikkel/ethernetcables.html

I know of more than one person who thought that the order did not
matter, as long as you keep it the same on both ends of the cable. For
short cables, that is true enough. As you go longer spans, though, some
configurations will be unreliable because of inductive effects. It's
best to just follow the standard.

At any rate, I hope that you can resolve your problem.
 
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