Where do I get a Cat-5 splitter?

Hi all, I need an analogue/digital splitter to fit into a patch-panel which has Cat-5 sockets. I have the domestic-type splitter as supplied by Eircom for example, but although the jack on the line side will fit the patch panel socket, the Cat-5 cable jacks are too big to fit the splitter's Phone and DSL sockets. Does anyone know where I can get a suitable splitter?

Thanks in advance.

I have a feeling that if you're sending digital data on Cat5, then a 'splitter' won't work. You'll need to get a router or a switch.

(I don't know much about this, apart from installing my own home network.)

Try Maplins or Radionics. Maplins prices are OK, Radionics are expensive.

Can you confirm you are running a phone extension over Cat 5, and thus want an DSL splitter with an "ethernet" (RJ45) plug on one end, a DSL filter in the middle, and phone and DSL sockets (RJ11) on the other?

They may be hard to get off the shelf. You might have more luck looking for a RJ45 to RJ11 adapter, plugging that into the patch panel, and plugging the domestic splitter into the adapter. Who terminated your phone line in your patch panel, and how did they suggest you connect a phone/modem to it without such an adapter?

If Maplins and Radionics don't have what you are looking for, they might have the adapter I mention. Alternatively they may be able to make something up.

Make sure you describe what you are looking for as I have above. A "cat5 / ethernet splitter" is a very different beast, used to run two independent ethernet connections on the same cable (by using the spare pairs in standard Cat5 for the extra connection). I suspect the previous posters assumed you meant ethernet.

MugsGame said:

Can you confirm you are running a phone extension over Cat 5, and thus want an DSL splitter with an "ethernet" (RJ45) plug on one end, a DSL filter in the middle, and phone and DSL sockets (RJ11) on the other?

Click to expand...

Thanks for a very comprehensive reply and sorry for not explaining myself better but it’ll be obvious that I’m not an expert when it comes to comms and networks so please bear with me while I try to describe the setup.

I have 3 phone lines terminating in a patch panel. I think I can safely say that the panel sockets are RJ45 which take what have been described to me as ‘network’ cables.

2 of the incoming lines are patched into a phone switch (Panasonic TEA308) and from there back to the output side of the panel, which in turn connects via Cat-5e cabling to RJ45 sockets around the office. The sockets are in pairs and are numbered – the phones being connected to the even numbers.

The 3rd line carries broadband which is patched to a router and firewall. The outputs are patched to the output side of the patch-panel and so to the odd-numbered sockets in the office. The comms equipment was installed by a subsidiary company of Eircom and the phone system by a private company. The comms company said that they didn’t normally stock splitters but were able to let me have what I now know to be the RJ11 type as originally described. They are unable to help me otherwise.

I would like to take advantage of the analogue side of the broadband line for a fax machine/phone which doesn’t need to go through the Panasonic switch. It seemed simplest to split the analogue/digital line at the incoming patch-panel socket and then patch the analogue side directly to a designated number on the outgoing side of the panel.

Does that suggest that unless I can get a splitter which plugs into the panel and has RJ45 on the output side also, I will be looking for RJ45/RJ11 adaptors on both sides of the splitter?

Apologies if I haven’t explained the situation properly.

That's a lot clearer thanks.

Just to explain that an RJ11 DSL splitter does two things
1. Feeds the phone line wires from one socket to two.
2. Removes (filters out) the DSL signal from the socket marked analogue/phone.

Particularly for 2. it makes sense to use the RJ11 DSL splitter you already have.

I think the best solution is what you tried oriiginally! Connect your RJ11 splitter directly to the patch panel RJ45 socket where your broadband phone line is. Then take two standard phone or modem cables (RJ11 plugs on both ends, with the wires passed straight through). Connect one between the splitter's DSL socket and the DSL port on your firewall/router, and connect the other between the splitter's analogue port and your fax machine (or back into an input port on your patch panel, if you want to patch it somewhere else in the building.).

Things would then look something like

That should work, assuming your comms installer used the middle pairs for the phone line, so you can just plug an RJ11 connector into the RJ45 socket. I think this is all you were missing originally, so apologies if I over-complicated things. When I wrote my original reply, I'd forgotten that RJ11 plugs are physically compatible with RJ45 sockets (It's a few years since I've been near a patch panel!). If you have analogue phones, look at where they connect to the floor or wall socket. You will probably find an RJ11 plug on the phone cable going into an RJ45 socket.


If your RJ11 splitter (the body, not the connector) is too wide to fit into your patch panel, just get a short phone extension cable (RJ11 plug on one end and RJ11 socket on the other) and insert that between the panel panel and the splitter.

Let us know how you get on.

Your instructions worked perfectly, MugsGame. Thank you very much. Another classic example of the way in which subscribers to this Forum unstintingly provide advice and share their hard-won knowledge and experience.