sundance-communications.com/forum Forums Computers & Programming Computers, Software, Accessories Cat 5 greater than 800 feet

What is the best way to handle a 100BaseT terminal 800 feet from the hub? I have a client that needs to run a group of terminals across a warehouse. I know Cat 5 limits at 333ft. I never had the need to run something more than 400 feet in the past.

Cat 6e ought to work for you.

If you absolutely have to have 100Base performance, I'd do it as follows: Run multimode fiber between your locations and put a media converter at each end. Allied Telesyn and Digi (among others) make these units, available for about $110-150 each. Assuming that the "group" of terminals can be run from one switch, you can use the patch cable from the media converter at the far (terminal) end as an uplink to a switch for the terminals. On the source end, just plug a patch cable from one of your switch ports to that media converter. Sort of like:
Switch Port -->MC-->Fiber-->MC-->Switch--> Terminals. If you have any other questions, post or e-mail me.

openwire-
CAT 6e only means the physical media is capable of conducting a signal at a specified "speed." This presumes, too, that the media is within specified length. Over an 800' distance there will be so much signal loss that packets will be continually dropped. Don't forget, when a data packet is dropped, the CRC realizes this and requests retransmission. There will be an abnormal number of retransmit requests, to the point that the network connection may well time out. You have to do something to keep the signal strength at an acceptable level throughout the distance, hence my suggestion for media converters, which are active devices. You could achieve a similar result by using switches each 300' of the run. I'd argue against this option due to an increased number of points of failure as well as it being an inelegant solution. Side note: I've had 10Base work over CAT 5 at distances well exceeding 300 feet, but as your communication rate increases, the signal becomes much more sensitive to drop and other interferences.

An easier option (in my eyes) than using those units is to figure out what kind of switch your customer has. If they've got a switch that will accept a fiber uplink card, then get that and use multimode fiber like Rover said, but instead of those devices he was talking about -- just uplink via fiber, much easier.

If it doesn't have to be 100BaseT, but just has to be close -- then you could use a set of DSL modems that are capable of point to point connections (flowpoint, paradyne, etc. makes them) and some of those will go up to 39Mbit.

Nick

You can also buy a couple of cheap hubs and put them every 300ft or so since each hub is a repeater.

here's what i'm going to do for a customer this week.

i'm running 600' (but the modems i'm using will go up to 10k) of cable between buildings.

i found sdsl modems for pretty cheap (you'll need 2).

i go from ethernet to sdsl modem to 1 dry pair wire to sdsl modem to ethernet.

done it for another customer. works great! the sdsl modems will only do 2048mbs but it's alot cheaper than fiber and 2-100mbs transcievers.

What brand of modems are you using, as well as -- what type of configuration? Does the pair cross over?

Give us the complete setup so that we can use the same idea. I've only done it with paradyne transcievers.

Everyone seems to have hit most of the highlights!

Fiber uplink/downlink between hub/switch is probably the best way. It avoids ground-loop problems that are prevalent in old warehouses.

Second-best is the media converter to fiber route. I've bought several media converters for about $50 each on ebay, and they seem to be readliy available, then use a 3-foot patch cord into the hub/switch at each end.

And yes, I have used the hub-every-300-feet method when the customer is a cheapskate. The problem you run into is that most warehouses don't have 110-single-phase outlets where you need them, and there may be a 5-hub/switch limit between endpoints. That depends on the internal implementation of the hub or switch.

Another option might be an 802.11 AP and a Bridge at the remote end. You can get a high-gain antenna if there's signal-strength problems. 802.11b will do about 1000' in clear space. One caveat in warehouses is cardboard - it absorbs a lot of RF signal. Using this method, you can come out 300' to the AP, and 300' to the bridge, so they are only a couple hundred feet apart. Of course, there's all kinds of security issues by going RF, but it's cheaper than fiber.

Howard

chris,

I too would like to know what brand you are using, maybe some setup notes, and where to get them. You did say the transfer speed is only about 2 meg right? Anything faster?