Cabling Distances

[Accessdabbler]

Using 10BaseT or 100BaseT, what is the maximum distance that 2 computers can be? I've read 300m and 500m.

Also, if the network is setup to run in full duplex mode, can these distances be increased as there are no collisions?

Thanks.

 

[hexn]

The max distance that a single cable can run with no regeneration is 100 meters. After that, regardless of duplex, the signal has deteriorated so much that it may no longer be recognizable.

 

[smah]

In addition, before you even get to the 100 meter mark, you will probably not be able to connect at 100Mbps.

 

[Accessdabbler]

Inikis:
Yeeaaa, but if I do regenerate the signal, what is the maximum distance between 2 computers I can have and still have communication?


smah:
Maybe, but the specs say that 100Mbps is possible at 100m.


For example, if a company has a LAN for the office workers but needs to add a computer at the shipping office (a long way away but in the same building), what is the furthest that computer can be if I can only use CAT5 cable and switches, hubs, repeaters, routers, etc...

 

[edfair]

Specs say 500m. 5 segments of 100m each. But you might be pushing it.
You might also consider wireless with directional antenna. Should pick up some distance if you can get a decent path. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[jimbopalmer]

For one PC you may wish to try a pair of tut systems modems

http://www.tutsys.com/mtu/products/ethernetworking/xl_600ld_ether_repeat/index.cfm

that will increase you range, at reduced throughput, to 24,000 feet (7000 meters) over copper. it is nothing I would use as a trunk, but it will serve one PC. I tried to remain child-like, all I acheived was childish.

 

[juggy]

The way most of us do it nowadys is by installing Fibre between the links ie shipping back to computer room. I would recommend that you strongly advise against any half way house solution besides the cost isnt that dear and its a one off cost for the whole building if done right. Most cablers would tell you straight that 500 meters wont work unless you got really unlucky (Sorry if you did). As for segments 5/4/3 this would involve multiple switches /hubs etc to the destination ie computer room to store room 1 with hub and so on till you get to the end if you use switches you can do it easily but I stress again get fibre put in and the for a very cheap price some fibre to cat 5 convertors or a decent fibre switch.

 

[jimbopalmer]

Oops, I showed a link to the 600 foot modems, the longer distance modems are at the same site

http://www.tutsys.com/mtu/products/ethernetworking/mxl_2300/index.cfm

I agree with Juggy, if there is going to be more than one device out there, go fiber. I tried to remain child-like, all I acheived was childish.

 

[Accessdabbler]

EDFAIR:
Can you point me to a website that shows the maximum 500m limit and possibly a technical reason? I'm sure it has to do with the time it takes for the signal to run from one end to the other and back again.

Also, if there won't be any collisions along this path, can the limit be extended even further?

My question is a theoretical one. Yes, I'd probably use fibre but I want to know if it could be done with CAT5e.

Thanks.

 

[edfair]

Try a google search for "ethernet specifications". I've never approched maximum so I don't know what the distance degradation might be. But the sites you'll find will give you some good info. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[daronwilson]

The maximum length per segment of 100 meters has to do with attenuation, basically that is the limit you can push the electricity down the wire. I've done up to about 130 meters or so successfully at 100 mbs with good wire and fittings, but it is not wise to push the limit because hardware and channel are designed with specific parameters.

Now, the maximum length overall has to do with timing, as I understand it. Essentially it takes too long to get the packet to the other end, and get acknowledgement, so it may retry before it actually needs to causing collisions and little to no thru put.

The correct options include wireless, long haul modems, fiber, etc. It is not wise to put little switches in at each 100 meter segment and try to push it 500 meters or more. For the cost, fiber can be quite competitive in your specific situation.

Good Luck! It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com