Splitting ethernet cable for router connection

Question

I have a Ethernet cable that has approx speed of 250 Mbps but then I dont get enough range in one of the rooms, so I was thinking of splitting the main Ethernet into two cables and then sending one of that to a different room which has a router which transmits in pretty good speed. But I'm not sure how to split the cable into two. I've heard about network switches, but it shows something like 5-Port 10/100MBPS with the product title, which I assume 100 Mbps is the max speed? I'm not sure, can someone throw some light on it, because I want more than 100 Mbps to be transmitted from the wires. And will it work if one Ethernet cable be split into two where the two cables can be plugged into two different routers?

The arrangement might sound stupid, but there are other reasons behind it. The whole network concept just terrifies me.

Sorry, if this is not the right place for this question. Thanks in advance :D

Current setup: Network from my neighbours moden is bough to my routers LAN cable which makes wifi system here, but its pretty slow(might be a modem issue), connecting to a different modem fixes the network speed, but the new modem has less range, so I was planning to use 2 modems but with only one ethernet cable. Hence my idea to split the cable into two and give two ethernet to two modem.

Answer 1

Your question is very unclear, so I'll try address multiple interpretations.

It is possible to split a single physical Ethernet cable into 2 cables, but you will limit the speeds to 100 megabit, as you only have 2 pairs (ie 4 wires) per cable. The big limitation is that the cable needs to GI between the same points and you need 2 ports in your router. Unlike phone cable you can't connect 3 cables together to connect up 3 devices. (Although this is what your question asks, I don't think this us what you want to do)

The other alternative - which is not splitting cables but rather daisy chaining switches - is likely what you want. Yes, 100 megabit switches will be limited to 100 megabits, but you can pay more money and get gigabit ones. Its fine to connect multiple switches together, provided you don't create a loop. Is each switch should only connect to 1 other switch. If you need 2 virtual cables - rg for LAN and WAN this is much harder and more expensive as you need VLAN capable switches which are a lot more expensive.

As an aside, have you looked at Ethernet over power devices and mesh networking - these might offer you practical alternatives.

Answer 2

You'll need a 1000 Mbps switch (or 1 Gbps, same thing). The cable goes into one port, two other cables go out of any other ports.

But if you're actually going to connect two routers to this switch, you'll run into another issue: devices connected to two different routers won't see each other. So for example local network file sharing will not work, it will all go through the Internet. That's because each router creates a separate network.

What would work is connecting a single router where you wanted to split the cable and adding additional access point where you need better WiFi coverage and/or speed. Access points don't create a network, they simply broadcast the wireless signal for the network created by the router, so you're avoiding the two networks issue.

Alternatively, consider using the router with good speed but poor range + a good WiFi repeater. That's probably the cheapest and easiest solution, but YMMV, the repeater may have speed issues too.

The best, most reliable option would be to use wired connection. If that's not an option due to difficulties laying the new cable, you could add powerline adapters into the mix - these transmit network signal over regular AC cables you already have in your walls. Make sure to get ones that will be fast enough for your application (300 Mbps+, some headroom is always nice to have).