My boxes need help, or maybe I do?
November 6, 2010 3:39 PM   Subscribe

My home network collection needs help

I have a tendency to acquire, boxes, devices that force me to re configure and redo my home networking situation from time to time. Sometimes my wife and I consider this need to acquire more "boxes" somewhat of a problem, but for now I just need a little support.

I had to move my cable internet modem and my wireless router (Time Capsule) to a different part of the house and two issues have come up.

One is that I tried to split the coax coming into the house. One side for the cable modem, the other side plugging directly into my Sony TV which was giving me access to HD content. After splitting the incoming cable, the TV was fine, but I was unable to get internet? Is it possible to split this feed in order to have access to both internet and cable and if so, do I use something different than one of these?

Two is an age old question I have. The Time Capsule only has three Ethernet ports and I could use at least one more (for the newest box ATV2). Is using a router the only option I have to obtain another fixed Ethernet port? The thought I just had walking home was this.

If I get a Cable Modem with a built in router, can I then plug one of the ports from that router into the Time Capsule and redistribute the network that way?

I feel I probably know the answer to this, but thought it cannot hurt to ask.

Thanks in advance for your guidance oh hive mind.

posted by silsurf to Computers & Internet (16 answers total)
Best answer: you need to make sure the splitter you use is one that will work properly with the cable Internet signals - specifically, it should be either marked as such or be marked as one that will work up to 1GHz. more info about that. you may also have a bad splitter, or there may be others on your line - using a splitter degrades the signal a bit, and, if there are too many, the cable modem may not be able to get a decent enough signal to work.

you can use a standard Ethernet switch to add Ethernet ports to your Time Capsule. run a cable between one of the ports on the Time Capsule to the switch, and use the rest of the ports on both for devices. do not get a router - routers are designed to take internet in one side and share it out; cascading routers is (a) more expensive than just getting a switch and (b) can cause your network devices (or you) to get confused if you don't set it up properly. it's just plain easier to use a normal switch. I've used this TRENDnet switch before with good results. you can get one with 5 ports if you don't need 8. you can get one without the power management stuff too if you don't want that.
posted by mrg at 3:57 PM on November 6, 2010

Yes, regarding the cable modem you want a 1GHz splitter. Preferably, you would have only one multi-port splitter whereever your cable comes in. You want one that doesn't split evenly. In the example of a 3 way splitter, you want one that has a -3.5dB port that goes to your cable modem and two -7dB ports that go to other things. (as opposed to each port being -5.5dB relative to input)

If you're using a Motorola cable modem, hook it back up how it doesn't work and go to in your web browser and look at the logs. This will tell you if your problem is a splitter that just doesn't pass traffic back upstream or if the signal level is too low on the downstream. If it's the former, just get an appropriate splitter. If the latter, you need an unbalanced splitter like I described.

mrg's got it regarding the extra ethernet ports.
posted by wierdo at 4:55 PM on November 6, 2010 [1 favorite]

Response by poster: thanks!
posted by silsurf at 6:04 PM on November 6, 2010

Response by poster: Do you think this splitter would work fine?

Thanks again!

posted by silsurf at 7:21 PM on November 6, 2010

No, you don't want a satellite splitter. You want this one, or its three way cousin. They're the ones my cable company provides. They've always worked perfectly for me.

Thus far, no cable company is putting anything up over 1000MHz, and unless you have DOCSIS 3, your cable modem almost certainly isn't even capable of using anything higher than 860MHz.

You might want to temporarily put the cable modem back where it used to be and check your signal levels before buying another splitter, though. If they're marginal, any splitter will probably be a problem. In that case, call your cable company and tell them your signal is too low. They should come out and fix it at their expense.

Ideally your signal to noise ratio will be at least 35dB or so before putting in the splitter and the upstream power level no more than 47-48dBmV.
posted by wierdo at 7:43 PM on November 6, 2010

Agreed with wierdo, in theory. The cable company is responsible for making sure you have a good signal. It may be difficult convincing them of this. You should definitely try, but bear in mind:

- they are likely going to tell you that any cables and splitters they they didn't provide aren't good enough. Sometimes that's true, sometimes not.

- it might be a difficult process, involving more than one visit from cable techs.

Check your cable bills; there is usually a flier in there that lists the prices for installation. It might be to your advantage to pay the $40 to have them to the install.

Also, before someone says it: an amplifier is probably not going to be the solution. Amplifiers do two things: they make the signal "louder" and they introduce noise. Amplifiers are used to maintain an already good signal that has to pass through a lot of splitters or long cables. They don't fix a bad signal.

And any amplifier you get will need to be cable modem ready since the cable modem is a two way device and the return path needs to be clear, or preferably amplified too.
posted by gjc at 6:58 AM on November 7, 2010

Response by poster: thanks, thanks and more thanks.

One last query. Is this the best order of data flow?

Cable at wall->splitter->cable modem->Time Capsule->Switch (from one of the ports on the Time Capsule)
posted by silsurf at 8:08 AM on November 7, 2010

It depends on how much traffic you've got going between which devices. I'd tend to lean toward running cable modem straight into the switch and then everything off that. That way they all get equal connection to/from the internet. What you want to avoid is daisy-chaining too many switches. Better to get an 8-port (or more) switch than to hang several 4-port ones off each other.

There's also something to be said for using a gigabit capable switch. They generally have the ability to move a greater amount of traffic, even when it's only connecting at 100mbps. Several 100mbps devices talking to each other (like streaming high-def movies) would be more likely to get bogged down through a 10/100 switch vs gig-E. I did this for three Tivo DVRs pulling video from each other. It kept the 100mbps Tivo traffic from slowing down everything else just by replacing the 10/100 switch. The switch was better able to juggle the 'freight train' of bulk traffic from the DVRs while still letting everything else get through.
posted by wkearney99 at 12:46 PM on November 7, 2010

Best answer: the way you have it is fine (i.e. cable modem->Time Capsule->switch). don't hook your cable modem straight into the switch - the Time Capsule is what's actually making it so all your systems can use the cable modem's Internet connection, and if you remove it only one machine will be able to get on. (if your cable modem has a built-in router, this would be different, but it seems that yours doesn't. you can do that with a modem with a router built-in, but it'll also require you to reconfigure your network - the cable modem router would be taking over certain services your Time Capsule does. easier to do it the way you've noted.)

it also may be easier to put the cable modem back where it was and instead run Ethernet between the cable modem and Time Capsule than run coax to where the Time Capsule is. I'm not sure why you wanted to move it, though, so that might not actually be a good plan. (this wouldn't work for me, for instance, because I've got all my network crap on a UPS. no good to have one thing across the house and not on a UPS.) you can run Ethernet cables a long way before it's really a problem. keep the cable under 300 feet and you'll be OK.

I do agree that there's no sense in buying a 100Mbit switch. gigabit ones are cheap. the 8-port one I linked to was all of $40, and you can get 'em cheaper if you want. you shouldn't link together too many either (so buy one with more ports than you think you need - I wish I'd bought the 8-port initially instead of the 5 I bought) but it's not really a big deal unless you have a huge network. additionally, your cable modem is most assuredly not anywhere near the size of your local network, unless you're not in the US. the highest I've seen for cable is 50Mbps - a gigabit network is 1000Mbps. you'll run out of Internet pipe before you run out of local pipe. (more is better for stuff on your local network, though.)
posted by mrg at 2:06 PM on November 7, 2010

Do you have a router somewhere in the picture, silsurf? Does your cable modem have one built in?

As far as switches go, as long as you don't have more than two (three is OK for 10/100, but not for 1000, IIRC) in the path between any two network devices, you should be fine, which means if you hook things up in the way you propose, you should be fine, but will have no room for expansion beyond replacing the existing switch or refactoring the network.

I agree with wkearney99 that if you have the extra money, a gigabit switch is a good idea. You can get an 8 port for $40 or a 5 port for $30. If you don't have the scratch, it's no big deal, but it'll make your backups faster if your computers end up plugged into the switch instead of directly into the time capsule. I prefer not to have to concern myself with which switch port I plug things into.

If you do have a router somewhere external to the cable modem, the link between the cable modem and the router doesn't count, but if you don't, you can't add another switch. ( might or might not work depending on stuff I'm not going to get into)

Also, regarding an amplifier, if you do need to put one in, you want to get a weatherproof one that you can mount outside at the closest possible point to the pole/pedestal/whereever your cable comes from. As gjc mentioned, amplifiers also amplify noise, so if you amplify the signal far on down the chain where the signal strength is already low, it won't do much, if any good. An amplifier is an absolute last resort, however. The cable company should take care of this for you. Sometimes they don't. That's why most people hate 'em. ;)

Also, you might check to see if they have an inside wiring maintenance program. For something around $2 a month the inside wiring (and thus signal levels everywhere) become entirely their responsibility and they're contractually obligated to make it work. Usually I buy it when I need them to come out for something I can't be sure isn't in my own wiring and take it off a few months later, but Cox lets me do that. Just something to think about.
posted by wierdo at 2:15 PM on November 7, 2010

On not-preview, skip my rambling and listen to mrg. ;)
posted by wierdo at 2:17 PM on November 7, 2010

Response by poster: I got my five port trendnet switch and installed everything in the order prescribed.

Everything works great except I stil cannot get the cable to split.

I have tried two different splitter, both are rated 500-1000mhz with -3.5db on each output. I actually had the atronix one listed above as well as another one.

I guess it is time to get the cable company involved, unless there are any other ideas on how to at least test what is going wrong with the split?


posted by silsurf at 11:09 AM on November 13, 2010

If all the coax involved is the thicker RG-6 type, yes, it's time to get the cable company involved. The thinner RG-59 has a lot more loss per foot, especially at high frequencies. If you call them out and there's obvious RG-59, they'll point at it and say "there's your problem." Even if it's too short a length to possibly be causing a problem. A few feet shouldn't be an issue except in the most marginal situation. A hundred feet would be an issue in almost every situation where you're trying to receive more than analog TV. (the analog signals are lower frequency, so have less attenuation in RG-59)

If your TV has a signal strength display and it's possible to move it, you could try it in both locations and compare the readings to see if perhaps it's a problem with the new cable, but it seems unlikely that the cable is a problem unless it's either a really long run or it got nicked/stripped/cut somehow.
posted by wierdo at 11:38 AM on November 13, 2010

Oh, are any wall connectors or other connectors involved in any of this? If so, make sure they're all attached securely. If a wall connector, pull the plate off the wall and make sure the incoming cable is screwed down tight. I once had a problem with interference making it into my cable and causing certain digital cable channels to drop out. Turned out to be a loose connection on the back of one of the wall plates.

The cable company's repair person should have a test meter they can use to check for ingress.
posted by wierdo at 11:44 AM on November 13, 2010

Response by poster: I was using these Monster Cable 6 footers that I had lying around, it crossed my mind that it might be about those, but it is such a short distance.

I think I have two short RG-6 pieces I can try.

posted by silsurf at 1:57 PM on November 13, 2010

Response by poster: Here is an update and another question to boot.

After trying new cables and two different splitters I called TWC and set up an appt. The guy came out and was able to get the connection going, though it really seemed a bit feeble. Then we had some rain and the whole network went down again. I was able to find one of the three cables leads that come into the house was capable of sustaining a connection, but that was it.

I made another appt with TWC and this time the guy really went to town. He discovered that the existing split under the house was lying a pool of mud, that the copper inside the main lead had turned back and that the cable from the pole to the house was way too old. So, he started over and changed everything out.

At the same time I opted to treat myself and up my speed to a new high speed 20mips access they are rolling out.

This requires a new cable modem:

Motorola Surfband SBG6580

Everything is hunky dory, except one thing, I need to get my Apple Time Capsule back into the mix because it is my Time Machine Backup. The Time Capsule is a router/hard drive and was acting as my wireless gateway, but now the Motorola is the Wireless Gateway. I was not home when the TWC serviceman set up everything, so what I need to figure out now is:

How do I use the Motorola Surfband as a modem and not a router and continue to use my Apple Time Capsule,


How do I stay with the Motorola Router and use my Time Capsule simply as a Time Machine backup drive on the network, turning the wireless and routing capabilities off??

Any thoughts great appreciated.

posted by silsurf at 10:34 AM on December 7, 2010

« Older Filtering Twitter - I'm sure it's simple, but how...   |   Help me find my dream jacket Newer »
This thread is closed to new comments.