The service comes into the basement with a coax to the ISP’s modem. The modem is in bridge mode and sends the signal upstairs to my router via Cat 5. The router provides 3 hard-wired internet connections as well as wireless.
I want to bring the modem upstairs and use it for internet (eliminate the router). It is a combo modem/router I was told.
The problem is that there’s no coax running upstairs. Can I use the Cat 5 line to bring the signal from the coax downstairs? I know that at work we used to do the opposite: use coax wiring to provide ethernet. This was done using “baluns”
Agreed, there is usually a “demarc box” on the exterior of your house with a splitter between the coax from the pole and the coax to your house. You should be able to easily rerun the coax yourself.
Keep in mind though, cable company supplied modems are typically worse than the average home router you’d buy from Wal-Mart. Using it as your wireless router may work great for your home layout or it may not.
As Dark Sponge said, the simplest solution to what you’re trying to do is to find where the cable feeding your modem starts, disconnect it, and run new coax to where you want it to be.
DOCSIS doesn’t work over UTP. Different method of shielding/separation.
You could try to pull a coax through the wall with the Cat 5. Note that you will almost certainly spend as much on Coax connectors and cable as on a replacement for your existing router.
For my own setup I prefer distinct devices for all major roles: Modem, router, switch, Wireless AP. I find the combo-boxes provided by my ISP to be lacking. (Router has too few features, Switch has too few ports and features, AP is in the wrong place)
There’s no simple way to use UTP to substitute for cable; the hardware to do so (if possible) would probably cost more than hiring a cable guy to pull the necessary coax wire, since it is a specialized application. You’re better off using a double-ended female connector and running more coax cable to upstairs. Or… if you have enough ports on your home router, turn it into a switch/access point.
(Basically - turn the ISP modem into a router, it will provide DHCP to the network. Disable DHCP on the home router, and voila! it’s a switch. With Wifi, it’s also an access point. Hook what was the feed to the WAN port of the router to one of the 5(?) LAN ports. and everyone is on the ISP modem’s network. Just be sure the router has an address on the Modem’s network range.
DHCP hands out IP addresses to each device, including the address of the “gateway” - where to send packets for outside the network to the rest of the world. The modem/router will say "pick me!’ if it is handing out addresses. The Router will give out its own address if it is DHCP server. Disable DHCP, and the router does not hand out addresses, but still switches between LAN ports (typical router has about 5) and to/from Wifi.
You can also extend your wifi if you have ethernet to another room - just do the same trick with another router; turn off DHCP and wire it in, with the same Wifi name and password. Your devices will connect to the nearest, strongest wifi. The only downside is wherever you roam in the house, as long as it can see the original base, it won’t switch to a closer one. )
You can use baluns and twisted pair to replace CATV coax, but the care and cost required to make it work correctly is actually greater than that required to make a simple coax extension lead work. High speed TP has to be treated with the same care that coax would (no sharp corners), and terminated with same care the optical fiber requires (although the termination equipment is cheaper), and the permitted length is shorter. Since it’s connected directly to the CATV, any problems you create are problems on the CATV network.