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Suggestions For a Coax-To-Ethernet Solution?
watanabe writes "I just moved from a house with Cat5e wiring to a house with ... a whole bunch of coax cables. Like, my living room has five coax cables coming out of a hole in the wall. All of them go back up to my attic.
The house is big, (and I like it, thank you), but I have realized that our digital usage pattern (media server + squeezeboxes + remote time machine backups to a linux box) will not work without wiring. I am currently bridging some old Linksys WRT54Gs to the right places, but of course, that slows everything down.
This got me thinking: 100mb ethernet is four wires, yes? And I have four wires for every two coax cables. What about a two coax-head -> ethernet jack setup? Has anyone done this before? Searching online only gives me $100+ coaxethernet transceiver type boxes. At that price, a HomePNY system would make more sense.
I'm willing to solder if I have to, but I first wanted to get advice and holes shot in my plan, if there are any."
If the coax was installed when the house was built, then the coax is probably stapled to the wall studs. If the coax was installed "after-market", then this trick might work.
</2cents>
"Glory is fleeting, but obscurity is forever." - Napoleon Bonaparte
Cat5 cable is what they call "UTP" - Unshielded Twisted Pair. Essentially, the losses and electrical noise of each pair of wires is canceled out because instead of comparing individual voltages, they compare differences of voltages between each wire in the pair. If you try to hook up an ethernet cable pair using a coax wire, you're going to end up with one wire (the shield) picking up the electrical noise and the inside wire won't pick up the noise. This is going to just make not work well. It'll work for short distances (just like if you crimp an ethernet cable but mess up the coloring so the pairs aren't matched) but over long distances of 20+ feet, it is just going to crap out.
PLUS... Dude, you're going to want gigabit eventually - and it uses 8 wires and is even more sensitive.
Bite the bullet - use the coax as a guide and hook up an ethernet jack in every room that needs one. Use CAT-5E cable or CAT-6 cable so gigabit connections will work. And then buy yourself a gigabit switch, and piggy back it onto your WRT54G to handle the internet routing (or buy a gigabit router). Good luck!
-Bill
I'm surprised no one has already mentioned MoCa,. Several companies make MoCa adapters that runs 100Mb/s ethernet over Coax cables: http://www.google.com/products/catalog?q=MOCA+adapter&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&cid=2590185696454305965&ei=PoR9S5uIC4mWtge8z5GfBQ&sa=X&oi=product_catalog_result&ct=image&resnum=1&ved=0CBQQ8gIwAA# And read all about it on Wikipedia: http://en.wikipedia.org/wiki/Multimedia_over_Coax_Alliance
Mike @ The Geek Pub. Let's Make Stuff!
Except 10Base-2 is 50ohm coax, while TV coax (which is probably what he has) is 75ohm. Nope, not going to work.
Damn, I wanted to use a cute unicode omega, but apparently
Do this and run new Coax alongside, as well as a slip line for any future wire pulls you may have in mind. Just be aware to use duct tape liberally and if you don't mind the mess, some line-pull lube would go a long way for tight fits. You can then put a punch-down in the attic and run patch cables from the punchdown into a switch in the closet in the floor below the attic. I recommend that if you get a 12-block punchdown (should be relatively cheap), then run all twelve patch cables down to the closet, even if you are only using half of them. It will save you some work later on.
Also, check building code in your area, as you may have to buy plenum insulated Cat6e as opposed to the cheaper PVC. Some jurisdictions actually restrict the use of PVC, even when it is behind a wall.
I went through and did this for a friend quite a few years ago (replaced all his phone cabling with Cat6e) and had an electrician friend of mine give us advice before we started. The electrician said we were OK to run the cabling ourselves, but we had to use plenum since that was what code required. The cabling was twice as expensive as PVC, even when bought in bulk. We also ran slip lines, which has been a god-send for my friend since he had to then follow up a year or so later and run more lines through to his home theater.
It won't, no way, no how. The capacitance of the coax cable will screw the whole thing up. You'll get relfections and crosstalk *everywhere*. What you need is an old fashioned 10Base2 card designed for coax, you need terminators and you need to make sure the cable is of the right impedance.
Paul Anderson
"I drank WHAT?!" -- Socrates
Far cheaper to pay someone to run cat5e for you. Around here it costs $100.00 a run for cat 5 runs under 120 feet. that includes new wallplates and termination at each end.
Do not look at laser with remaining good eye.
Searching online only gives me $100+ coaxethernet transceiver type boxes.
Anonymusing wrote:
If the wire is nailed down (therefore not free to be pulled), perhaps he could use an Ethernet-over-coax adaptor or this one from Netgear.
Amazon wrote:
Ethernet-over-coax Converter/extender: $148.99
Netgear MCAB1001 MoCA Coax-Ethernet Adapter Kit (Black): $180.91
I imagine the OP was looking for a cheaper way to do this.
Just wanted to clarify that Ethernet refers to a standard, not a cable. You can have ethernet over UTP, coax, fiber, etc...
If the coax in your walls is RG6, that's probably better than Cat5.
Homes with Fios or UVerse have nifty little coax to rj45 boxes that allow for the home networking setup.
--alop
yes it does. you impedance match the ends with baluns.
I did that a LOT back in the day of 10base2 when the office owner would not pony up for running wires.... yet he paid 2X that for baluns and impedance matching...
Do not look at laser with remaining good eye.
Hmm... I think you're replying to someone who is saying that you can use the coax to pull UTP cable. While using the coax instead of UTP won't work, using it as a pull cord should be OK.
Not very likely. Instead, they use one of the "cable modem" protocols, perhaps DOCSIS.
U-Verse uses HPNA for the coax networking.
First, to the original question. D-Link makes a product that lets you do this. Not that I'm recommending you buy their product, but they claim that, due to bandwidth limitations, your performance would be lower than 802.11n. Now D-link is doing some signal processing, before the packets hit the wire, so I suspect that trying to run a raw signal over coax will produce less than reliable results.
To all those people recommending using the coax to pull cat5 - that probably won't work. Generally the coax will be stapled or otherwise tied to the studs.
Slashdot used to be friends with Unicode until vandals started abusing Unicode bidirectionality.
Um, "complete failure to understand parent post"?
This thread is talking about using the existing coax runs to wirepull Cat5 through the walls, not trying to run signals through the coax.
In theory, one could use four 50 ohm coax cables to run 100BaseT - Two 50 ohm single-ended coax cables can be used to form a 100 ohm differential connection, same characteristic impedance as Cat5 but with a hell of a lot more shielding and isolation.
However, if they were 75 ohm TV connections, they're useless as anything other than a physical cable to attach another cable to for the purposes of pulling it through the wall.
retrorocket.o not found, launch anyway?
Yup, and quickly realize how much slower that is that his current wireless solution..
How old is the house? It it's not too old, the telephone may be run on cat5. You can actually piggy-back ethernet and telephone on the same cat5 cable. I did that in a couple of rooms in my house and it worked great.
You do realize ethernet originally ran over coax, right? Google '10BASE2'
Only problem with that is 10Base-2 ran over 50 ohm impedance coax while CATV coax is 75 ohm impedance. The mismatch would reduce the power delivered to the receiving end and set up a standing wave that would deform the wave shape, possibly causing errors.
This ain't rocket surgery.
It became unpopular when it became too expensive to use. It was always expensive as that is the nature of coaxial cable, but when UTP became deployed, it was more and more and more realized that there was no need for coax and its terminations. Coaxial cable works beautifully up to high frequencies in the units or tens of GHz, but twisted pair is just as good into the hundreds of MHz. When your baud rate isn't going to exceed that, why mess with something more expensive?
;)
As for the question posted by timothy, it is by another slightly electronics-illiterate poster. The statement, "This got me thinking: 100mb ethernet is four wires, yes? And I have four wires for every two coax cables. What about a two coax-head -> ethernet jack setup?" needs to be examined here. You can't just assume that since Ethernet "is four wires" you can use any four conductors as a layer 1 transport. That might bring house electrical wiring into the equation. No, we can't do this since we are talking about transmission lines, and everything has to be impedance matched, and the PHY has to be able to handle what the symbols look like on either end of the line. We aren't talking DC here--there is a lot more involved to high speed communication links than "wiring stuff up."
So, I would either go with a coaxial media adapter or use the coax to do new Ethernet cable pulls.
Attach a CAT5/6 AND a string, and pull like hell. You'll be glad you have a string in the wall when you want to pull CAT7.
Just remember, when you attach something to the string, always attach a new string too. It sucks when you finally finish pulling a run, only to have forgotten the replacement string.
I was just searching for this same thing today and a friend of mine suggested this product:
http://www.netsys-direct.com/proddetail.php?prod=NH-310CEKIT&cat=27
It's a 200Mb ethernet-over-coax solution that makes use of existing coax installs and uses traditional cable. We'll be testing it soon for a 200 metre install.
I send you this message in order to have your advice.
The review on the site look good. If it's not possible to pull cat5 in, I'd say that's his best best.
I researched this and found that the Actiontec MI424WR router that Verizon provides for their FiOS service makes a nice, high-speed coax-ethernet bridge. You can purchase them used from BCD Electro. I bought a pair to utilize the coax under my house that ran from the main cable splitter to my office. I re-routed the cable under the house to the location of my wireless router and hooked everything up so that my desktop internet connection went this way: desktop <-ethernet-> MI424WR <-coax-> MI424WR <-ethernet-> WRT54GL. There are guides on how to set them up to act as bridges and it's pretty simple. For the cost of a decent USB WiFi adapter, I have hardwired connectivity that provides me with 2x the throughput as my now-dead USB WiFi that it replaced.
The HPNA Coax adapters are only about $70, and the best solution if you can't repull new Category 5 cable. Google Products shows plenty of stores with them in stock. You will get 100Mbit and the reliability of the ones I've used has been quite good. They are also available in phone line versions if that's the sort of wiring you have around.
The crimping pliers I use cost about ten bucks, and I've produced one bad cable out of twenty - and that was the first one I'd ever made. When that happens you cut off an inch and redo.
Plus, if you're installing it fixed to a wall you'll likely use box sockets. The terminals on those are usually screw fit.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Try these converters. http://www.veracityusa.com/products/products.php
No no ... you're right actually
Good people do not need laws to tell them to act responsibly, while bad people will find a way around the laws-Plato
Basically, yes. Even 150Mbps isn't all that great. I happen to be one of those people who uses 802.11n for the house network because I couldn't run cables, and frankly, I'm rather unhappy about it. Big files don't copy as fast as they could, sometimes (though not as often as I feared) video stutters, etc.
Wireless is cool tech, but it is totally inferior to wires in situations where you can run wires. And maybe some day there will be wireless gigabit, but imagine how fast wired ethernet will be then.
The ones I got were pre-labelled and didn't require any crimping (just stripping the outer shell off). It looked more or less like this - http://www-personal.umich.edu/~csev/hng/book/06wiring/female.jpg
Those clipped into the faceplate and my walls look nice and professional -- even though I did it myself. Regular pre-made cables from the wall to my devices.
Second that suggestion.
However, pull gently, and coax it the whole way (pun not intended). If the coaxial runs through pipes, you'll probably run much less risk of stripping or breaking the Cat5/6. Almost none if you find a gallon or so of wire lube at Home Depot or Lowes and grease the hell out of the new cable as it enters the pipe. Just be sure to trail a strong cord along with it so you have another pull if you want to pull another line in later. If you test it and it doesn't work because a wire stretched too much, you can just pull another (trailing in another pull string).
Also, test the wires directly by twisting them all together at one end and connecting a bell/battery gadget to pairs at the other. When you ring the bell, both wires are good. If it doesn't, one or both are bad.
And if it were me, I would absolutely work on getting an updated Cat5/6 line in the house. Barring that, go wireless. The coaxial solutions are more expensive and in my experience, rarely come close the current wireless options. Good luck!
The right tools for the right job: Get a 110-punchdown tool (or one with 66 and 110 blades) for $60-70. Don't bother with the stupid plastic ones that come with the cat5 wall jacks-- you need one that's spring loaded and sets the wires with a nice solid THUNK. You can get the wall plates and inserts from any big box store now, and Radio Shock (sic) and some hardware stores. Screw terminals- gaa. You want me to strip and fan out 8 wires (no cheating by just doing the blue, and green pairs) and then mess around with a little screw driver? No thanks. I can terminate about 5 to 7 of them per hour, including the occasional re-do, with a punch tool. 'Sides, if you want to work the best, you have to maintain the twist right up to the terminals. Try that with screws. I run gigabit over my home-terminated jacks and home-made jumpers all the time, and I don't have any errors or retries at my switch ports.
That's what I was thinking.
100BaseT is on twisted pair 100 ohm impedance.
Simply wiring up to the shield and conductor of the coax won't work worth a damn (50 or 75 ohm will cause bit error rates like hell).
Get a balun transformer that matches 100 ohms to 75 or 50 ohms (depending on your cable) and two cables + 4 baluns = one 100 meg run.
That said, the baluns have to work at 125MHz, and you'll find they are quite pricey. You'll likely want to simply pull new cable.
-nB
whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
Really? You might try telling that to Netgear or D-Link or any of the other companies that make Coaxial Ethernet Bridges.
This whole story could have been avoided if the poster knew the right term to Google.
"Don't blame me, I voted for Kodos!"
Because coax was so unreliable it would make network admins cry.
In the good ole lan party days, the network would be disrupted every time someone needed to connect or disconnect a pc. Sometimes you had T piece that was a bit faulty and that also nuked the network. And when you had 12 machines on the network, finding the source of the error was even harder.
Performance was only a secondary reason for it's demise.
You don't need impedance transformers in this case. 75 Ohm terminators (in place of standard Ethernet 50 Ohm) will do the trick. These are much cheaper and can be hacked together at home if not found in stores.
10BaseT cards have high impedance transmitters and receivers that can drive/receive wide range of cable impedances, as long as the cable is matched at the ends (to avoid reflections).
I am all fingers when crimping cables but I punched down around 20 cables in around 2 hours.
You have two choices for the (good) wall sockets. Either pay a high price each, or a low price but buy the tool. When I wired my home I paid the low price each + highly priced tool and got the tool back the next day for a full reimbursement ;)
Yeah, that's called theft in the retail world. You bought a product, used it for its intended purpose successfully, and then returned it to the store for a full refund. The retailer is kind enough to offer this return service under the assumption that returns are because it didn't work for you, was defective, or some other honest reason. But it did work for you, wasn't defective, and your return for a full refund was dishonest.
They have a now-devalued used return item that they can no longer sell at the full price. You deprived them directly of that value as if you'd stolen the money from their pocket.
You are a thief and an asshole.
Yes, in fact you can use the Verizon FIOS wireless router for bridging Coax to Ethernet. My cable boxes get IP addresses from my Windows DHCP server and download the On-Demand through my Linux-based router, all through the FIOS bridge router.
Before FIOS used the full routers standard, they use a Coax transciever and you can pick them up for about $100, sometimes cheaper, for 100Mbit over existing Coax.
- It's not the Macs I hate. It's Digg users. -
And just as importantly, a single collision domain, making maximum throughput even harder to attain.
If you went to engineering school: you were not paying attention. If you got this from a book or website: you need a new source, or possibly learn this stuff again. This would be filed under: transmission line fundamentals.
A cable can be approximated by having some distributed capacitance between the conductors, and some inductance along the conductors. These of course can be expressed in C/l (say F/m) and L/l (H/m). The combination of the inductance and the capacitance per unit-length gives you a characteristic real impedance that is independent of length.
You terminate the line with the characteristic impedance so that all the energy going there is absorbed and dissipated.
A real transmission line has a spec in ohms/meter: the loss. The loss can be modeled as a series resistance and a parallel conductance, which forms a real impedance (resistance) in ohms/meter. However the loss is a dissipative factor and for the short runs typically encountered in Ethernet (including Coax) can usually be ignored.
Made by motorola, they are coax to ethernet bridges, 400mbs on the coax side 100mbs on the ethernet side. the default on the coax side is the 169.x.x.x addresses and bridge the ethernet. I use 2 in my house for areas that don't yet have ethernet, and they get the eth address from my dhcp server probably cost prohibitive unless you can get a deal on them somewhere
wanted: one clever sig,apply within
pfft, kids these days. you can make them quite simply yourself with very cheap components (one of which could even some cat-5 wire pulled apart), hams have been doing it for decades. tons of info on the web, try "balun"