Help? How long is TOO long for an ethernet cable?

[Arschloch]

At the company where I work, someone is changing offices, and as a result he needs a longer ethernet cable for his computer.

I know that I've read that ethernet cables must be less than a certain length. Does anyone know what this length is? 30 feet? 50 feet?

Thanks for the help. I need it!

Arschloch

 

[ttn1]

Wired properly, you should be able to make a 100 m (330 ft) cable and still have it work. If you are less than 200 ft, I wouldn't worry.

 

[Arschloch]

<< Wired properly, you should be able to make a 100 m (330 ft) cable and still have it work. If you are less than 200 ft, I wouldn't worry. >>


Shoot, that's interesting.

I read a couple of sites that have said 100 m, and I've read a couple of others that have said not to go past 30 feet!

There seems to be no consensus. Or has the consensus just changed?

 

[sohcrates]

<< [There seems to be no consensus. Or has the consensus just changed? >>



If 30 feet was a real limit, i'd be screwed!

I've easily got runs all over my place of well into the hundreds of feet, and it works just dandy.

 

[ScottMac]

The STANDARD is 100 meters. But there are qualifications: 90 Meters of that must be solid wire cable, 10 meters (5M at each end) can be stranded (for flexibility). Stranded cable has much more loss, and poorer performance than solid-wire cable.

Using only stranded cable greatly reduces the acceptable length overall.

FWIW

Scott

 

[Arschloch]

Thanks for the help, guys!

I will notify my boss of the 100 m limit.

For everyone who responded to this thread, and who has user ratings enabled, I will give each of you a 10 rating.

-Arschloch

 

[nihil]

it is possible to use cable lenghts past 100m for ethernet if neccessary. you would just have to use a signal repeater.

 

[ktwebb]

Slap a hub or swith in a wiring closet if you wanna extend past the 100M barrier. And by the way, there is a definitely a "consensus". 100 meters.

 

[brisco]

100m is what the industry standard says.

If you nead to go further, use a repeater or a different media like fiber. In personal experience, on a network that didn't have much traffic I have run 110m without a problem. Just depends on how much traffic your network has.

 

[kylef]

<< Slap a hub or swith in a wiring closet if you wanna extend past the 100M barrier. >>



Do NOT use a hub to extend beyond the barrier. A hub will not increase ethernet segment length. Only switches, which use per-port buffering, can accomplish that feat.

 

[Tanner]

328' is the maximum length from the switch, through the run, from the box on the wall, through the patch cable, to the ethernet card.

I spoke w/ a cabling expert today (he ran this region's division) and he said that he's run 1500 feet before, and it will work. But you will have loss (he said that in some cases, that's a serious understatement), and it will be very, very slow.

so, U know the req's now...AND U know that U can go beyond them, but there are the consequences.

 

[L3Guy]

<< Do NOT use a hub to extend beyond the barrier. A hub will not increase ethernet segment length. Only switches, which use per-port buffering, can accomplish that feat. >>


I want to clarify that last point. There are several distinct cases, and need to be addressed separately.

10 Base T. Conservatively, 3 repeaters can be used. If your office is using a switch, repeaters could extend the distance an additional 300 Meters. On the other hand, 10 Mb fiber is inexpensive and can go 2 Km.

100 Base T from a switch. A repeater can be used to extend the distance, and each can be up to 100 meters. The penalty is that because of the hub, only half duplex operation will be supported.

100 Base T from a hub. A class 2 repeater/hub is allowed to interconnect to one other Class 2 hub with a 5 meter cable. No Idea if the home stuff if class 1 or 2. In other words, a second repeater does not buy much distance.

Switches will allow the extension in all cases.

Summarize: Switch always, hub @10mb "always", hub @ 100Mb, caution.

By the way, its 100 Meters for twisted pair, 185 Meters for 10 Base 2, 500 meters for 10 Base 5, and 50 meters for a transceiver cable.
We just assume that you are talking 10BaseT or 100 BaseT.

Regards;

Doug

 

[DIRTsquirt]

DOH! open mouth insert foot hehe

 

[kylef]

Yeah, it seems to me that there's just no reason today to use a hub/repeater to extend ethernet segments when unmanaged ethernet switches are only about 10% more expensive than hubs... Store-and-forward switches may increase the latency a few tens of microseconds, but you gain an entirely new segment!

 

[wlee]

Another way get a really long cable run with a standard cat5 switch and Ethernet card is to use Cat5---> fiber transceiver. That will give you a 2000' + length. It gives you good isolation from RF noise as well, but the cost is VERY high per node. Something like $150 per transceiver and you need one at each end of the cable run.