Sorry Bill but yes you can they use 2 pairs each out of the 4 pair cat 5 (standard utp uses the green and the orange pairs, these also use the blue and the brown pairs to provide the 2nd connection), you need to use them as a pair.
Cat 5 economisers have been around since day dot but wouldn't recommend them.

They are OK if you only need 10/100 speeds though

So how do you explain the remark in the advert:

Remark:
1.This splitter does not replace a hub.
2.This Ethernet splitter allows two computers to share one Ethernet line, but it doesn't support both computer to connect onto the internet simultaneously.

In reply to a post by billford:

So how do you explain the remark in the advert:

Remark:
1.This splitter does not replace a hub.
2.This Ethernet splitter allows two computers to share one Ethernet line, but it doesn't support both computer to connect onto the internet simultaneously.

The splitter doesn't join the pairs at all - you get two separate 100megabit connections over one Cat5/5e/6 cable - and you MUST use a similar splitter at each end. If you use gigabit these WON'T work as Gigabit uses all the wires in the ethernet cable. 100mbps and 10mbps don't.

That's why 1 is true - the splitter doesn't connect the two inputs together. ( a hub/switch would ).

And thus why 2 is true - they're not connected !

Badly written and probably misleading info for those who don't know what they are looking at or how networking works

1. Punters may assume that you can connect 3 devices together by using the splitter.
2. As explained, splits the cat 5 cable into 2 circuits by using the blue/brown pairs which are not normally used for 10/100 networking.

In reply to a post by Alexir:

Sorry when I said Why I meant why won't my idea work.

I know the sensible option would be to run ethernet from the modem to the router and then use the lan sockets of the router for various needs eg a homeplug. Trouble is the router is a bit of a distance from the modem and is powered by an extension cable. I don't want to plug the homeplug into the end of the extension as I'm told it's better to put a homeplug directly into the mains.

You will lose speed but it will work. However as you have Fibre you probably want speed.

The mains socket is back where the modem is, so I hoped to put the homeplug and modem there together and have a short ethernet between the two (with a splitter in the middle sending the signal to the router too). Make sense?

I now know the splitter I suggested has issues so that two items can't operate at the same time (which is a bit weird) so perhaps it's an academic question anyway.

Because the splitter doesn't join the wires. A cat5/5e/6 cable has multiple pairs within the cable. The splitter lets you use the pairs independently. You don't want that.

You also need all your internet traffic to go from any box *through* the router and then the modem and onto the phone line. If your internet traffic from a PC tries to use the modem directly it just won't work.

The router & modem are a pair. On ADSL for years we've bought them in the same box for convenience.

In reply to a post by Alexir:

I don't want to plug the homeplug into the end of the extension as I'm told it's better to put a homeplug directly into the mains.

Try it, you'll probably find it's absolutely fine.

In reply to a post by Rockh:

Badly written and probably misleading info

Fair enough... After all these years I should know better than to take at face value what it says in the advert

Be careful.

I've used an identical product (looking at the picture here) to join 3 ports together.

It depends which is more accurate the dodgy description or the picture!

Also some gigabit adapters struggle over a 4 wire 2 pair link, though setting the speed to a manual 100Mb sometimes fixes this.

Regards,

mark.

There seems to be a bit of a range of opinions about this (I've learnt from the thread- I hadn't heard of Cat5 Economisers before ), so I think my judgement would be that for less than a couple of quid it's worth a shot