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Suggestions For a Coax-To-Ethernet Solution? 608

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."
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Suggestions For a Coax-To-Ethernet Solution?

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  • by mtippett ( 110279 ) on Thursday February 18, 2010 @02:11PM (#31187324) Homepage

    If you have lots of coax running through pipes and if it is free, then use the coax as a wirepull to rewire the house.

    Cat5 provides many more options than cat5.

    • by 0racle ( 667029 ) on Thursday February 18, 2010 @02:13PM (#31187362)
      Actually, I have found that Cat5 provides just as many options as cat5.

      I admit though, my testing may not have been exhaustive.
    • by Hatta ( 162192 )

      I was going to say the exact same thing. I needed to bridge my upstairs and downstairs networks. I was able to use the existing runs of coax to guide my cat-5 up the wall. Just bought a new face plate with an RF-45 and F-connector and widened the existing hole a little bit.

    • by UID30 ( 176734 ) on Thursday February 18, 2010 @02:16PM (#31187414)
      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.

    • Aargh. Cat5 provides many more options than coax.. My bad.

    • If the wire is nailed down (therefore not free to be pulled), perhaps he could use an Ethernet-over-coax adaptor [amazon.com].

      • Re: (Score:3, Interesting)

        Or this one from Netgear [amazon.com].

        Anyone have experience with these?

        • Re: (Score:3, Informative)

          by Reece400 ( 584378 )
          The review on the site look good. If it's not possible to pull cat5 in, I'd say that's his best best.
      • Re: (Score:3, Informative)

        by Lumpy ( 12016 )

        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.

      • watanabe wrote:

        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 [amazon.com] or this one from Netgear [amazon.com].

        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.

    • by Lumpy ( 12016 )


        because I bet that it is all crappy RG59 cable and not RG6 or RG6Quad that would really be needed.

      If the house was wired more than 7 years ago the coax in it is pretty much garbage.

      It's also not hard to run new wires in existing homes, I dont know why people are so scared of it.

    • by Afell001 ( 961697 ) on Thursday February 18, 2010 @02:27PM (#31187626)
      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.
    • I'll second the "use it for a wirepull" sentiment, though not the cat5 > cat5 sentiment.

      No point in haggling with crappy old coax, and, happily, coax is really durable, so it's well suited to being a pull line.

    • Re: (Score:3, Funny)

      by vivin ( 671928 )

      Cat5 provides many more options than cat5.

      That's so zen.

    • Have any of you really tried this in a big house? Unless the house isn't that big (the OP says it is in fact big) and the coax was retrofitted and not installed permanently (which is quite possibly the case) trying to use the coax as a pull for cat5/6 is a bad idea.

      There is a chance that the coax will reveal an ideal conduit (such as a hollow wall running from the basement to the attic) if you follow it carefully, from the living room down and then up. Using it as a pull from one end to the other is likel

  • and run new wiring? Does the old coax run in channels or conduits?

  • by Glendale2x ( 210533 ) <slashdot@ninjamon[ ].us ['key' in gap]> on Thursday February 18, 2010 @02:13PM (#31187358) Homepage

    Coax gives you one braided shield and one center conductor to carry RF. It's not even remotely like UTP.

  • 10Base-2? (Score:3, Interesting)

    by Chris Lawrence ( 1733598 ) on Thursday February 18, 2010 @02:13PM (#31187360) Homepage
    Well, 10Base-2 [wikipedia.org] uses coax. I think I have an old hub that still has a coax connector. :)
    • Re:10Base-2? (Score:4, Informative)

      by marcansoft ( 727665 ) <<moc.tfosnacram> <ta> <rotceh>> on Thursday February 18, 2010 @02:19PM (#31187478) Homepage

      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

    • by Jim Hall ( 2985 )

      Well, 10Base-2 uses coax. I think I have an old hub that still has a coax connector. :)

      I was going to write my own "10base2" comment, but instead I'll just reply to this one. Yes, your coax cables are essentially 10base2 cables - but may have a different connector. Sounds like you're willing to do a little work - so, get a cable conversion tool and add some correct connectors.

      Once you have that, you'll need to have some 10base2-to-10baseT converters. You can probably get them cheaper elsewhere, but here's one at Amazon [amazon.com].

      My first workplace was wired entirely with 10base2, even in our server roo

  • by your_mother_sews_soc ( 528221 ) on Thursday February 18, 2010 @02:13PM (#31187370)
    I have AT&T's Uverse for phone/TV/internet and its set-top boxes communicate over coax. They are using IP over coax, since the router shows the boxes' IP addresses as though they were on a an Ethernet network. The boxes run Windows Media Edition, for what it's worth.
  • Twisted pair, man (Score:5, Insightful)

    by Spy Handler ( 822350 ) on Thursday February 18, 2010 @02:16PM (#31187408) Homepage Journal

    100mb ethernet is four wires, yes? And I have four wires for every two coax cables.

    The four wires in your coax are not twisted. It's not gonna work.

    Pay $100 for those coax-ethernet transceiver things, or string some Cat5e. Seriously, if you can afford to buy a big ass house then what's another couple hundred??

    • My mind has been boggling at how bad an idea his plan is. The conductor and shield in coax have capacitance between them, it's an unbalanced transmission line. There'd be noise and cross talk and impedance mismatches causing reflections.... It's like running the poor signal through a meat grinder.

    • They don't have to be twisted; they're shielded, which is generally even better. Of course, there's really only one wire in each coax cable (plus a shield).

    • by MMC Monster ( 602931 ) on Thursday February 18, 2010 @03:36PM (#31189016)

      The extra hundred is probably something he'll have to explain to his S.O.

      Sometimes it's easier to freakin' sell the house. :-)

  • by Cassini2 ( 956052 ) on Thursday February 18, 2010 @02:16PM (#31187416)

    If the coax is sitting loose in the walls, you can use it as a pull cable to thread in replacement UTP cable.

    Old Ethernet worked over Coax. I just doubt you have the correct kind of Coax. Also, my experience with residential cable installs is that they tend to have damaged Coax cable, so it is pointless even trying to use it for high-bandwidth applications.

    Finally, while it is theoretically possible to substitute 4 "pairs" of twisted pair with 4 Coax cables, my suspicion would be that you would have severe impedance mismatch problems. It might be good at 10 Mb, where the old Coaxial ethernet worked. I doubt it would handle modern 1 Gb Ethernet signals. Also, modern Ethernet expects all 4 pairs to be of approximately the same length, and it is unlikely someone would have 4 matched-length pairs of coaxial cable sitting in their wall.

  • by name_already_taken ( 540581 ) on Thursday February 18, 2010 @02:16PM (#31187424)

    If you have access to the attic, it may be a full day's work to wire the whole house, but you'll be far better off pulling the correct wiring into place. Buy a 500ft box of cable and the appropriate wall jacks and plates and make a day of it. It's not hard with a fish tape or fish sticks (those bendy fiberglass poles for running wires).

    I have been using an 802.11N bridge to connect my upstairs printer/scanner/thing and I have another computer up there with a wireless bridge and it's a pain compared to the situation downstairs where I ran Cat6 to a patch panel in the basement.

    Buying all the cable, jacks and plates has cost less than the single 802.11N bridge, and I have gigabit Ethernet for my devices. The wiring is simple and once it's in place it's done.

  • Bite the bullet! (Score:3, Informative)

    by CyberBill ( 526285 ) on Thursday February 18, 2010 @02:18PM (#31187446)
    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!
  • As others have said, it's better just to use the coax cable to rewire the house. Ethernet at high data rates requires a differential and high frequency cable twisted pair. Coax does not give you any of this. There's also the problem that the impedance of a coax cable is orders of magnitude greater than cat5, so you'll either have to have a high-powered driver and matching terminator at both ends or a modem.

    All in all, it's not worth the effort unless someone out there has already designed something like tha

  • MoCa (Score:5, Informative)

    by MikeDataLink ( 536925 ) <`mike' `at' `murraynet.net'> on Thursday February 18, 2010 @02:19PM (#31187470) Homepage Journal
    • Re: (Score:3, Informative)

      by kazinator ( 783384 )
      Those Netgear MoCa adapters work well (up to ~ 100Mb with decent coax and no splitters in their path). They blow away the performance of an 802.11n network. I made the switch 6 months ago and never looked back. They are also compatible with most existing MoCa systems. i.e., if you have a ActionTec Verizon Fios Router, it will act as a third adapter. So if you have Fios, this is any easy/efficient way to add access to your network without going wireless. For those you in apartments or with shared coax,
  • Category 6 is better for high speed multimedia, and the small extra cost is worth it.

  • "And I have four wires for every two coax cables."

    One of which is the shielding, and is subject to EMF interference, and one is the core, which is shielded, which would give you a potentially unbalanced system which would give you a lot of errors. Plus there's the issue of capacitance.

    If speed isn't an issue, you could always put a BNC end on the coax, and pick up some 10 mbit hubs from eBay with both RG45 and a BNC coax connection. You'd be stuck at 10 mbit, but it's probably the cheapest/easiest solution.

  • Many of the posts suggest to pullout the coax and rewire with cat5e. My question to the community is why not Cat6? When I bulit a small network in my house I concluded that ca6 is slightly better than cat5e, especially for gigabit speeds. If you're going to wire your house why not use cat6?

  • Related Questions (Score:4, Interesting)

    by godrik ( 1287354 ) on Thursday February 18, 2010 @02:23PM (#31187546)

    If you were building a house today, which kind of connectivity would you set up ?

    Since the expensive part is probably paying someone to put the cable, it could make sense to set up both gigabit ethernet and optical fiber in all rooms. Do any slashdotters have some opinion on that ?

    • by Corf ( 145778 ) on Thursday February 18, 2010 @02:31PM (#31187740) Journal
      A conduit containing both CAT6 and some fishing line to pull through whatever's in vogue once CAT6 will no longer cut it.
      • by jayteedee ( 211241 ) on Thursday February 18, 2010 @03:33PM (#31188944)

        I disagree on the conduit containing Cat6 and the fish line. I'd keep the Cat6 separate and put in the conduit with the fish line though. Conduit is definitely the great idea, but having to run more than 1 cable through a conduit is a lot more work than an empty conduit. And forget running the gray PVC or the flexible gray conduit (outdoor rated stuff). Both are way too expensive and totally unnecessary for low voltage wires (except maybe in a few weird states with goofy regulations). Use cheap polyethylene tube used for sprinklers (1/2") which you can get in 500 and 1000 foot rolls.

  • The key here is "twisted pair". I'm not an expert by any means, but my understanding is that the twisting design limits electrical interference and noise. Without that, you're likely to get an extremely error-prone connection.

    Wiring a house isn't actually that hard or expensive, presuming you either have an attic to drop wire from or a crawl space to move up from. It takes some time, but do it yourself and you can do it right with Cat6, some higher quality coax for video distribution, and more. Look up "Str

  • Would not recommend using the coax as a solder hack-job to RJ45 connectors. Running all new cabling is easy provided you have the proper tools (flashlight, fish tape/rod, box of cable, cordless drill, long drill bit 3/8-1/2" head, box of draw-string, and a helper)

    Do yourself a big favor, and when you pull in your shiny new ethernet, tie in some drawstrings so you never have to repeat the process.

  • You really can't adapt this - the impedance for this coax is likely 70 ohm (for cable tv) and cat 5 is 100 ohms. You could build a balun, but you'd probably have some weird distance/speed related issues you've never had before. Anyhow if anyone had the parts it would be these guys:

    http://www.blackbox.com/Store/Detail.aspx/CATV-Balun/IC448A-R2 [blackbox.com]

    I know that's the wrong way, but it gives you an idea of how much you'd have to pay.

  • First, any ethernet media converters you with coaxial as the medium, are going to be 10BASE-T 10Mbit connections. You will no longer be able to utilize 100Mbit across ethernet. Second, attempting to solder the wires from a twisted pair cable, and pinning it out over 4 shielded coaxial cables, is going to result in an extreme signal degredation and is completely out of the picture as a viable option. The posters above me stated that using one of the original coaxial cable as a base for pulling a snagless
  • The easiest way is to get some Ethernet to coax bridges: eBay [ebay.com], Google [google.com].

    If you elect to replace the coax with Cat5 or Cat6, DO NOT try to pull it yourself. If you fuck it up, you'll end up paying someone else a lot more than if you just had an electrician do it in the first place.

  • Sure, youre dropping around 100 bucks per drop [newegg.com] (less if you go with actiontec), but it saves you time and energy doing a cat5 conversion. The bitrates are pretty good too, although that depends on the quality and length of your wiring.

    Powerline AV isnt bad, you can get a steady 40-50mbps with it, but that's pretty much wireless-N speeds, which is a lot cheaper.

  • Why not wireless? (Score:2, Redundant)

    by H0p313ss ( 811249 )

    This sounds like a question from the 90s.

    Why not just make the jump to wireless? Do you really need more that 56Mbps on a home LAN?

    I did that six years ago when I started having to deal with my kids having their own computers on their desks to do homework for high school. (Mostly because after five minutes investigation I decided I never wanted to go into the insulated attic of my new house ever again if at all possible. Blown insulation is cheap an effective but it kind of makes the attic unusable without

  • Clarification (Score:2, Informative)

    by alop ( 67204 )

    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.

  • Nope (Score:3, Informative)

    by joeyblades ( 785896 ) on Thursday February 18, 2010 @02:32PM (#31187772)

    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.

  • Another alternative (Score:5, Informative)

    by joeyblades ( 785896 ) on Thursday February 18, 2010 @02:35PM (#31187824)
    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.
  • by litui ( 231192 ) <litui AT litui DOT net> on Thursday February 18, 2010 @02:37PM (#31187870) Homepage Journal

    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 [netsys-direct.com]

    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.

  • by soulsteal ( 104635 ) <soulsteal@[ ]37.org ['3l3' in gap]> on Thursday February 18, 2010 @02:38PM (#31187876) Homepage
    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.
  • If you can't repull (Score:3, Informative)

    by zeet ( 70981 ) on Thursday February 18, 2010 @02:42PM (#31187958)
    The HPNA Coax adapters are only about $70, and the best solution if you can't repull new Category 5 cable. Google Products [google.com] 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.
  • by rickb928 ( 945187 ) on Thursday February 18, 2010 @02:45PM (#31188024) Homepage Journal

    You cannot use RG-59 (CATV COAX) in any useful fashion for networking. Don't bother thinking about it any more.

    Pull CAT-5 or better. Bite the bullet. Ignore the coax.

    Even if it's RG-6 or whatever, if it's F connectors (screw-on) forget about it.

    Now, if by some chance, you got RG-58 and BNC connectors, then you can maybe run 10MB over it. Another supreme waste of time.

    I suspect all the media convertors that claimed to drive 100MB over wacko coax are finally gone, since none worked worth a damn.

    And if you've got so much coax, you can use one as a pull string. At least for one run. You might be able to bribe a buddy to help you. Once.

  • by noidentity ( 188756 ) on Thursday February 18, 2010 @02:52PM (#31188112)
    In the current house I'm renting, I needed a connection between a computer in a bedroom and the living room, and didn't want to use wireless. There was some 6-conductor phone cable in the jacks, and a single phone line only needs two (I like having a landline), so I figured I could use the other four for 10BASE-T Ethernet. It worked once I got the pairs right (the phone cable is three twisted pairs, and I had to have TX on one pair, and RX on the other, rather than split across two pairs). There's about 100 feet of phone cable between the two. On the dining room end, the phone jack isn't next to the computer, so I ran about 25 more feet of 6-conductor phone cable to the desk for the computer and phone. Again I had to get the Ethernet pairs next to each other. In the end, 10BASE-T and 100BASE-TX work, though I notched it down to 10BASE-T just to be on the safe side, and my Internet connection is less than 1 Mbps anyway. And yes, I realize I'm probably broadcasting every bit of data I send across this connection, due to the phone cable being unshielded.

    Coax cable might behave a bit differently, because one of the conductors is exposed and can pick up signals, but the other isn't, unlike a twisted pair. Differential signaling relies on both picking up the same signal, so that it can be rejected at the receiver by finding the difference between the two. You mentioned it having five coax cables; with that, you could use four coax cables, with the outer layer grounded on each. This way neither will pick up much of anything extra. It sure seems worth a try to me.

  • what?? (Score:4, Interesting)

    by Lord Ender ( 156273 ) on Thursday February 18, 2010 @06:05PM (#31191968) Homepage

    You can afford a huge house, but you can't come up with $100 for a tranceiver? That's absolutely daft.

  • Cat5 (Score:3, Funny)

    by lotho brandybuck ( 720697 ) on Thursday February 18, 2010 @07:57PM (#31193306) Homepage Journal
    We have cat5 and they're worthless. They pee on my stuff, don't guard the house and require expensive stinky canned food.

"I prefer the blunted cudgels of the followers of the Serpent God." -- Sean Doran the Younger