Cat5E length

[drvnbysound]

I used to live by the idea that IEEE put forth with the Cat5E standard that cable runs should not exceed ~330ft. I have put switches in line with cable runs simply to repeat the signal to mitigate the problem.

It wasnt until a recent cable run where there was going to be a DIFFICULT task of running power to a particular location in order to put a switch in line, and I decided to put max length to a test... on a ~425ft cable. I initially terminated the ends and made the run into a crossover cable, enabling me to connect 2 laptops end to end and run ping tests as well as throughput tests. Unfortunately one of the laptops was borrowed and I no longer have access to it, but I got ~80Mbs out of the cable (throughput may have been limited by NIC card in laptop). In any case, that was well above what I needed for the link so I found it to be perfectly acceptable for my application.

I was just curious if anyone else has done any long CAT5e runs and had similar success?? Or even with other cabling such as RS232...

 

[WayneW]

Sure, we used to break the RS232 rules for length versus baud rate all the time... it is a total YMMV.

But when things don't work, nobody in their right mind will help you

 

[kmitchell]

I've worked as a hardware engineer on ethernet gear for many years and I can tell you that the IEEE standard is just that, a standard. Some companies read that as a recommendation while others read it as a spec. Any company worth anything will guarantee their equipment to work at 100M and test to much more than that. I've always tested to 130 meters which is approx 426 ft. How well it will work in all conditions and with different manufacturers' cable is anyone's guess.

And as Wayne said "Don't call us if you have a problem with it".

Ken

PS. If you can get away with 10Mbit do that since it won't be nearly as sensitive as the tri-level signaling used on 100Mbit.

 

[drozwood90]

if you go 10M, instead of 100M, you will cut your distance down by 1/10.

Personally, when I was designing layouts for that stuff, I'd make sure to put in switches for repeating, or use fiber. You can always stick a PoE switch in there to alleviate the power problem.

Then my job turned into designing test equipment for crashing cars into walls. Fun stuff. Even today, I am doing stuff nowhere near where I started. I love engineering.

--Dan

 

[kmitchell]

if you go 10M, instead of 100M, you will cut your distance down by 1/10.

Dan,

What do you mean by "cut your distance down by 1/10"? 10baseT or 100baseT are both 100 meters max over Cat5.

Ken

 

[iqvoice]

I used to live by the idea that IEEE put forth with the Cat5E standard that cable runs should not exceed ~330ft. I have put switches in line with cable runs simply to repeat the signal to mitigate the problem.
I was just curious if anyone else has done any long CAT5e runs and had similar success?? Or even with other cabling such as RS232...

In the office building I work in, there are multiple cable runs that are longer than 330 ft. They seem to work okay. Now in your case, you don't mention where you are running the cable, just that it would be difficult to add a switch. This makes me think, perhaps you are running it outdoors, building to building or the like? Which reminds me of a cable run I did in a warehouse one time. It was close to 300', and it worked just fine during the summer time-- but not so well in the winter! It was a somewhat unheated warehouse, and the signal quality definitely degraded when the temperatures fell into the 40's. Coincidence?

 

[drozwood90]

if you go 10M, instead of 100M, you will cut your distance down by 1/10.

Dan,

What do you mean by "cut your distance down by 1/10"? 10baseT or 100baseT are both 100 meters max over Cat5.

Ken

Ken,

Fading memory, I stand corrected!

I was thinking that 10 base-t was 100', 100 base-t was 100meters. Correct me though, if you went Cat-6 wasn't the standard 150meters, not 100?

My bad. It's been a long time since I've delt with this stuff! Last time I was doing this, I was designing VOIP phones...so it wasn't my issue, as the ethernet chip did all the heavy lifting!

I do remember, that's why we just did up-linking with fiber. It cost more, but was FAST and reliable, especially when you had guys that knew how to the polish the ends of the fiber!

My favorite was we had a school my company wired up. It was an 'L' shape. The main patch panel was in one end of the L. They wanted the secondary panel in the other end. I suggested an outside run, but was voted down. So, we ran fiber. It worked...but that long of a run...man...

--Dan

 

[drvnbysound]

In the office building I work in, there are multiple cable runs that are longer than 330 ft. They seem to work okay. Now in your case, you don't mention where you are running the cable, just that it would be difficult to add a switch. This makes me think, perhaps you are running it outdoors, building to building or the like? Which reminds me of a cable run I did in a warehouse one time. It was close to 300', and it worked just fine during the summer time-- but not so well in the winter! It was a somewhat unheated warehouse, and the signal quality definitely degraded when the temperatures fell into the 40's. Coincidence?

Very good picking up on that

It is actually on the rooftop of a building in Yuma, AZ. I certainly dont think there will be any issue with cold temperatures there However, I do have concerns with the heat. The cable is outdoor rated to 175-deg so I think it will be OK... I suppose only time will tell