Ethernet splitters

[_Bat_]

Has anyone ever used these before? They basically split one network point into two.

 

These sound ideal for a few of our classrooms. We only have two network points in each classroom and as we now have a few spare PCs, I have been asked if we can relocate a small number of them around the school. Unfortunately this means we have a lack of network points. We don't have the budget to start adding more points either.

 

Do you think it'd cause any problems if I used them in a few classrooms?

 

Cheers!

[Guest richard]

Couldn't you use a small 5 port switch instead?

[plexer]

If using 100mbit ethernet you will not notice any problems caused by using one of these.

 

Ben

[CyberNerd]

Ethernet splitters are bad news.

Cat5 is twisted pair for a reason - the wires are paired so that cross-talk and electrical noise are reduced. You may as well use some old bell wire and expect problems.

[limbo]

I think the way it works is that ethernet often only uses four of the eight cores in cat 5 anyway so it just takes the spare four and makes a new socket out of it.

 

So in theory if there is enough slack you could do it yourself - but it may be cheaper this way than buying the new modules and face plates.

 

I think that is right anyway - and the only downside is that it will not duplex.

[_Bat_]

Couldn't you use a small 5 port switch instead?

 

The reason I decided not to do something like this is cost. I can get hold of ethernet splitters for around £4 each (maybe less).

 

@CyberNerd

 

I suspected there might be issues, which is why I asked here first for confirmation. It's a shame... other then that, they are sooo ideal.

[plexer]

We have been using one in an ict suite for the last few years with no problems.

 

They still keep it twisted and untiwst no more than a normal termination would.

 

If you want to try em pm me you school address as I have a pair lying around doing nothing.

 

Ben

[mattx]

Have used them quite a bit on our network and never had a problem with them. Got me out of some sticky problems sometimes.

For obvious reasons don't try POE on them !!

[western]

We are a network company and have supplied them for years. THEY WILL DUPLEX! and they do use the spare pairs (croostalk noise - not an issue). The only downside is that if you ever go to a gig it will not work as gig uses all the pairs!!!

 

Use them they are great!

[CyberNerd]

ok, heres some info about how twisted pair works:

 

http://www.cirris.com/testing/twisted_pair/twist.html

http://en.wikipedia.org/wiki/Twisted_pair

 

but like I said, bell wire also 'works'.

[western]

so what happems when you use power over ethernet?

[mattx]

so what happems when you use power over ethernet?

 

Nothing special, it won't work over a splitter 'cos like someone has already said about the cores. I think POE uses the different cores.

 

http://www.olotwireless.net/catala/poe.htm

 

If you fancy having a bash yourself.... :-)

[western]

I actually meant with the crosstalk / noise @ cybernerd. I do understand how it works but thanks anyway Matt

[Geoff]

PoE uses pins 4 and 5 plus 7 and 8. So Pair 1 and Pair 4 respectively. What pins do the splitters use?

[western]

PoE uses pins 4 and 5 plus 7 and 8. So Pair 1 and Pair 4 respectively. What pins do the splitters use? )

they use the same i think

[_Bat_]

Thanks for the advice everyone.

 

Just about to send a PM now plexer.

[plexer]

Exactly 100mbit uses 2 pairs i.e 4 wires gigabit uses all 4 pairs.

 

To run poe to 100mbit devices it uses the unused pairs.

 

Therefore if you had 2 devices plugged into a splitter and also tried to use poe on it then something will get fried if it an unitelligent poe solution such as the dlink and buffalo ones that just push 48v down the wire instead of sensing if the device uses poe.

 

Ben

[SimpleSi]

Only cheat when youreally have to (and splitters are cheating)

4/8port switches are cheap.

 

regards

Simon

PS but the splitters will probably be more reliable

[Guest Guest]

TBH you should be starting to think about gig to the clients in the next few years - gunna have to run new cables at some point, may aswell do it now.

[Ric_]

You can get Netgear mini-switches for £20-odd quid for 5 or 8 ports. These are made out of metal and are very reliable plus you get more than one extra port.

[Ben_Stanton]

I Use a plitter in one classroom without a problem.

 

_bat_: I have a a couple of redundant 10Mb 'hubs' if you get really stuck...

[mattx]

I have a a couple of redundant 10Mb 'hubs' if you get really stuck...

 

Heh, I have plenty of those kicking around !!

[bishopsgarthstockton]

I have a 24 port switch sat on me desk does the job for me

[sidewinder]

We have a few of these in one suite as so many points are damaged and they work OK

I would far prefer not to have them but I really havent noticed any problems.

 

Its cheaper than fixing the points as that suite has them on posts rising out of the floor and they constantly get kicked

[ajbritton]

If they can make these, then surely it can't be that hard to make a faceplate with a built in hub/switch with say 2/4/8 ports. (hmmm...disappears off to the halfbakery...)

 

EDIT: DOH - I should have looked further down the page, then I would have found the 4/6 port managed hub in a faceplate!!