Networks How long can a RJ45 cable be?

Evening all

Does anyone know how long an RJ45 cable can be before you start getting data errors or bandwidth loss? I want to share my broadband connection between 2 pc`s, but the 2nd pc is upstairs, and will need at least a 15 metre cable - if it will work that is!

Anyone else running a v.long network cable with no probs?

Thanks in advance

 

they can be pretty long, think of large bulidings and such... its something like 150 meters before something bad happens

15m will be just fine mate

 

yeah, on lan-parties you usually need a cable of 20 metres or something

 

i am reliably informed that 100m is the max for a 1gigabit network, and 200m is the max for 100mbit

 

I thort it was 100m for 100mbit?? , u can make longer just u need signal repeaters or something dont u?

 

im running a networked cable modem throo 15m of RJ45 to my PC upstairs with no data loss or slowdown atall, so yah that would be fine

 

100mbit! I wish! hehe

Just to check - to connect 2 pc`s it needs to be a patch cable correct? As I need to know which one to steal er i mean borrow from work

 

2 pcs with no hub/switch then you need x-over (patched? prolly means the same thing ) cables

 

You can run any speed network through any length cable really, but the longer it gets you will get signal degradation, and the speed will slow itself down as it has to resend information.

This won't really happen for 100mbit networks before at least 100metres, so long as there's no high voltage power lines running near the cable for example (would increase the interference)

for a 10mbit network the range is higher, around 500 meters I believe.

you can of course stick a hub in the middle, which will act a bit like a booster, then you can have a whole kilometre of cable

but you can't normally buy more than 300metres in one piece anyway.

 

A Patch cable doesn't mean the same thing as a Crossover cable

Patch cables are cables which are generally shorter, and made for connecting your PC to a socket at the wall, or a server in a rack to a switch in that rack, for example.

Patch cables are generally made from a different grade of cable (which is more expensive) which is more flexible, allowing it to bend more easily etc.

Coloured cables with seem nobbly (ie you can see/feel the smaller cables inside them) are this type.


The long grey cables you buy in reels are not this type - and are generally only used for installed permanent cabling in offices etc.

you can use either grade cable for either job though, it's just not 'proper' practice.



As for a X-over cable:

one end should be: White-Green, Green, White Orange, Blue, White-Blue, Orange, White-Brown, Brown

and the other end should be: White-Orange, Orange, White Green, Blue, White-Blue, Green, White-Brown, Brown

(straight thru cables have both ends the same, and they can be in either of the above orders (as long as they're the same !) )

 

As far as copper based cabling goes this site has all the maximum recommended lengths:

http://www.homenethelp.com/web/explain/maximum-cable-length.asp

 

to paraphrase for phil:

a crossover cable is a cable that is wired in such a way that the send wires on one PC are the recieve wires on the other one. so both pcs dont try to send on teh same wire.

patch cables are short, and are used mostly in say a wiring closet where within a space of a few feet you need to make connections. so you dont need a long wire.

you can use patch cables to do a network, but chances are that youre gonna need something longer.

the efective length in feet for cat5 350mhz cable is 300 feet. i am using a 100ft cable in my network right now. that being said i do notice longer ping times on the other machine, and sometimes i will need to rfresh webpages cuz they dont always load right.

but its my parents machine, so who cares. they play solitaire and do spreadsheets.

and also power cables are alright just as long as you dont cross the cables. meaning that you can run the cat5 and the power in parallel, but the minute that the 2 intersect it gets much much worse then it would otherwise be.

i find it handy to put cables through central heating ductwork.

 

Thanks for all the advice guys - although I cant test any of it at the moment coz my main rig died for some inexplicable reason! Hopefully I`m getting it sorted tonight and can test out some of the ideas posted later on this week

 

got a m8 who uses 50 metres in a 2.5 story house

no what u r thinking how can u have half a stoy well they have a tall rof and turned sum of the attik into a bedroom which is fooking huge

 

I'm actually having real problems at the moment with RJ45 at home. At work I have installed cable and fibre links nearly 500 M in length, at home I cant get my laptop card connected to my switch properly...It's only 12 M. Grrrrrrr, I am doing nothing wrong, all textbook stuff, yet it dont work for nowt!!!!!

 

500 metres no bloomin wonder it aint working it has proberly droped out at round 200 metres who in the right mind needs a 500 metre cable ne ways

 

combined fibre and utp....to put a system into the middle of an airfield.

 

Soundz like a fun project... a little different.

 

funny i've got a box of 1000' of RJ45 and thats what i'm running my system on now...... 1000' of coiled RJ45.... no problems (of course i only actually needed about 10'..... but what the hell... it was cheap )

 

got it working... grrrr.....cheap crimper with a darn bent pin...