Avoiding RJ-11
February 11, 2008 8:56 AM   Subscribe

I’m planning the wiring for a new home, and I'm paralyzed by the variety of options for getting phone service throughout the house. Do I even need RJ11 any more? What's the best way to link up VoIP and POTS to a CAT6 home phone system?

My house: 4BR home, 4xCAT6 everywhere all wired back to central wiring closet, plus 802.11g wireless. Out in the country, so my only communications options are satellite dish (for both TV and high speed Internet) and Verizon POTS line. I'd like to avoid doing traditional phone wiring inside the house completely if possible. I’d like to use cheap VoIP service for calls, but I definitely want 911 capability

I’m not sure the VoIP call quality will be good enough long term, so it seems smart to plan for easy fall back to POTS service. Presumably I can always continue to use the CAT6 cabling inside the home to wire the phones. Has anyone successfully navigated this maze? Any suggestions on specific phone systems, routers, VoIP providers, or the MagicBoxTM that ties it all together would be greatly appreciated!

Basic requirements:
• Local telephone number.
• Telephones (8) in the home connected to wiring closet via Ethernet.
• Default outside connection via VoIP provider.
• POTS line to line-powered phone in wiring closet in case of power outage.
• Voicemail.

Wish list:
• MagicBoxTM = Ethernet phone router that features a hard-wired RJ-11 jack where I can plug in that line-powered phone.
• MagicBoxTM = When the internets are down but power is still on, calls can be made from extensions through POTS line.
• MagicBoxTM = Some kind of QoS monitoring that will use the POTS line if VoIP call quality is bad?
• Multi-line capable (at least 2 concurrent calls).
• Extensions for each person (6).
• Mailboxes for each person.
• Visible “Message waiting” indicator.
• Vmail delivered (copied) via email.
• Conferencing (3-way) and in-home conferencing between extensions.

I can dream, can’t I?
• Telephone interface to allow integration with A/V systems (mute sound on call).
• Wireless integration – switch my AT&T Wireless cell over to 802.11g when in the house.
• Telephones as intercoms (call the kids for dinner).
• Programmable “follow me” call routing for each extension, including routing to cell phones.
• Internet interface for changing settings remotely.
posted by JParker to Technology (25 answers total) 7 users marked this as a favorite
Asterisk should be your friend here. There are some more user-friendly (and feature-friendly) implementations than others, but it's the obvious way to go.

You can feasibly run VoIP on internal wiring if you're cut off from the local POTS service, but not simultaneously. But if you have an Asterisk server that handles everything, you can mix and match, using IP phones or ATAs w/ regular phones.
posted by holgate at 9:26 AM on February 11, 2008

Best answer: I hate to tell you this, but VoIP over a high-speed satellite TCP/IP link is probably going to be very jittery, because of the latency inherent in such a connection. Before you build out a system, make sure that you know the limitations of your data pipe.

With that said, an Asterisk or Callweaver box on a UPS in your wiring closet (plus a little specialized hardware, like an iaxy) can do everything on your list, including the dreams list, except for the integration with AT&T wireless.
posted by toxic at 9:32 AM on February 11, 2008

Best answer: And here we are: VoIP and POTS integration with Asterisk. Much of the conf-file and command-line stuff for Asterisk can now be down through web interfaces in custom implementations. You can even conceivably run an Asterisk server from an always-on machine in a VMWare virtual machine, though you might want to build a dedicated box. (Some routers also have space for a no frills asterisk server via OpenWRT.) The hardware isn't cheap, but it's no longer corporate-account expensive.
posted by holgate at 9:34 AM on February 11, 2008

Response by poster: Thanks, I have looked at Asterisk, and I agree that's the right direction. But as much as I love open source, I don't know telco and don't have the time (or the interest level) to figure it out from scratch. I need an appliance to plug things into.

I've seen trixbox, which is as close as anything to what I'm looking for, but it's obviously focused on businesses and telecommuters - extending VoIP beyond the home office. Do you know of any similar implementations for residential?
posted by JParker at 9:46 AM on February 11, 2008

I've had good luck with Vonage. The adapter that came free with it sits between your internet connection and your computer network hub and provides 2 standard RJ-11 jacks. Since it is the first point of connection to the internet it will prioritize a phone call over computer network traffic. I've been on the phone while downloading and did not have any problems with voice quality or my download speed. I'm using a 1.5mbps downstream 812kbps upstream DSL connection. I haven't noticed any bad problems with lag in any games I've tried, but I don't play very many games online so can't comment very extensively on that.

As for wiring that to the rest of your house, I would recommend just getting one of those cordless base sets that come with 4 extra phones. You don't need to plug those extra phones into anything.

Vonage has all the services you are asking for. It is $25/month for unlimited calling (local/long distance), and $15 for 500 minutes.
posted by nickerbocker at 9:52 AM on February 11, 2008

Response by poster: -- on preview --
toxic - Callweaver looks very powerful, thanks for pointing that out.
holgate - The onlamp.com article does describe exactly what I'm looking for in VoIP and POTS call routing and QoS, thanks for that as well!

I just hope you guys are going to clean up the mess when my head asplodes.
posted by JParker at 9:54 AM on February 11, 2008

2nding nickerbocker on the phone with one transmitting/charging base and other bases that you can place around the house and charge only. This is very convenient.

I imagine that if you try VOIP over a satellite internet connection, your conversations will be like those on TV (live via satellite) when the anchor asks a question and has to wait several seconds before the field correspondent's answer begins.
posted by Dec One at 9:59 AM on February 11, 2008

Response by poster: also toxic, thanks for that caveat emptor re VoIP over satellite. I have read in several places that cable is the recommended high-speed internet connection, but with some of the VoIP vendors touting service even on dial-up I figured I was safe. I have about a month before I make the final decision, so I'm going to switch my internet in this house I'm renting from Charter cable to DirecTV high speed internet and test it myself.

I'll still probably want to link up all the phones inside the house via IP, since that's cabled. Then I'll still have the IP to POTS interface in the wiring closet to figure out (home PBX?).
posted by JParker at 10:05 AM on February 11, 2008

Response by poster: Vonage might be the VoIP answer, but it doesn't address the POTS interface. The adaptor that nickerbocker mentions is, I think, only connected to the internet, not a POTS line. While it will let you connect non-VoIP phones to a VoIP network, that's not my issue.
posted by JParker at 10:09 AM on February 11, 2008

Response by poster: holgate - followed the "hardware" link in your reply and browsed around that site a bit, and found the TalkSwitch 284vs, which is closer than anything else I've seen to the kind of appliance I'm looking for. It's not cheap, but solves most of the problems mentioned above. Thanks again!

Now I'm just hoping that VoIP works OK over satellite...
posted by JParker at 10:28 AM on February 11, 2008

BroadVoice has a bring-your-own-device plan, meaning it's Asterisk-friendly. It has an iffy reputation for surcharging high use, but recent reviews seem more positive. Whether your sat-broadband has latency issues, you'll have to see, but I don't think there's a contract lock-in.

NerdVittles has custom-configured Trixbox VMWare images, and lots of tips outside the usual office config. This post, for instance, guides you through the IP bit of setting up a PBX, and you can then drop in the POTS stuff on top. That hardware PBX looks like sweet kit, but for the wish list items, you might want the configurability of your own box.
posted by holgate at 10:43 AM on February 11, 2008

Not sure if you've thought about this, but if you're running 4xCAT6 to each room, you'll have a lot of spare pairs running back to the wiring closet. If you need to, you can always take one pair and use it for POTS service, without running any CAT3.

If I was doing this, I'd probably use analog in the house just for simplicity's sake (no new phones required) and then run it into an Asterisk box in the wiring closet that would handle the A/D conversion and do all the VoIP goodness.

There are several commercial products (PCI cards) that you can buy that work with Asterisk and act as the inside-the-house POTS interfaces. Alternately, there are a few types of internal modems that are usable by Asterisk ... you'd probably have to eBay to find them (it's a particular Intel chipset, IIRC) but that might be the cheap route if you only want one or two lines.

Basically you just do that, and then you choose a VoIP provider who'll give you a phone number and let you make outgoing calls. It's probably one of the simplest use cases for Asterisk.

But before you start planning I'd either ask around on some Asterisk-specific forums or try VoIP over satellite to make sure it's going to work. I've had mixed luck running VoIP on anything except fast, low-latency connections. (But then again I'm picky; I want my 'landline' phone to sound like a landline, not like a cellphone.)
posted by Kadin2048 at 11:02 AM on February 11, 2008

I've seen trixbox, which is as close as anything to what I'm looking for, but it's obviously focused on businesses and telecommuters. Do you know of any similar implementations for residential?

Trixbox used to be called "Asterisk@home", and was initially designed for residential use (residential use by hackers, mind you, but residential use, nonetheless). It's really quite easy to set up. (And six extensions with voicemail for each is hardly typical for a residence... anything you use is going to be focused towards business users).

With regard to satellite, the gotcha really is the latency (the amount of time a packetized bit of voice data takes to get from you, to the satellite, to the ground again, then across the Internet to your VoIP provider). The overall throughput of a VoIP call is fairly low (throughput == the number of packetized bits that can be sent to you in a second), so yes, many codecs work just fine across a dialup connection, but that doesn't mean they're suitable for your dish.

The problem really is one of physics. Even on dialup, a slow steady stream of data will travel across wires and optical cables, at roughly the speed of light. Coast-to-coast and back in less than two tenths of a second? No problem. But if you've got to send that data to the Clarke belt and back, you've just introduced almost 72,000 km of distance to the equation. When you pick up the phone and say "Hello", that first syllable is going to take almost half a second just to reach your VoIP provider, as will any response from the other side -- and that sort of delay is the enemy of real-time communications, like voice.

VoIP systems use buffers to try to mitigate this, which introduces the sort of delay that you've heard on some very long-distance calls, but one side-effect of the buffers is a Max Headroom like stutter (jitter), when the datastream takes a little too long to arrive. I think that this is going to happen an awful lot with a satellite connection -- even if the delay doesn't bug you (or your callers).

You can very easily play with a softphone and FWD, for free, and get a sense for what the delay and jitter is going to be like. Generally the quality of a FWD call is going to be lower than one through a commercial VoIP provider... but if the delay and jitter makes FWD unusable, then I suspect that most VoIP will suffer the same fate at your location.
posted by toxic at 11:19 AM on February 11, 2008

VOIP and satellite details aside, here's one helpful nerd's description of using CAT5 to wire all his phones, with a wire diagram and decent descriptions of the issues he dealt with regarding his punchdown block. I've done this myself on a small scale, and it's quite easy. So no, you totally don't need to use RJ11 any more.
posted by dammitjim at 11:22 AM on February 11, 2008

Response by poster: Thanks, toxic and agreed on all points. I am pretty familiar with high end stereo, so I understand jitter. Probably a high dependency on the actual transmission protocols as well, which will vary by provider, hence my decision to test the VoIP on DirecTV which will be the satellite vendor I use for internet.

I agree with Kadin2048, too, that a landline ought to sound like a landline, not a cell phone. In a stairwell. Under water.

Based on the input here, I'm suspecting I'll be stuck with POTS for phone for now due solely to the satellite internet issue, but I'll be able to make sure I'm "VoIP ready" when the cable or the DSL lines get out here.
posted by JParker at 11:30 AM on February 11, 2008

Another consideration is resale -- I don't know how much it costs to wire POTS after the fact, but any buyer (in the near future) would likely consider the lack of it a liability.
posted by crickets at 12:14 PM on February 11, 2008

You could use Where as a base for creating an app that (shunts your phone into redirecting to your house/VOIP number) or (attempting to switch over to WiFi (if that function's exposed on your phone)) when it's spent over X minutes within Y yards of Z location.

Do note that the article that Dammitjim supplies a stock wiring diagram for phone-or-Network. I'm used to using bBoGgOrR (b=white/Blue, B=Blue/white, same for Orange, Green and bRown) - You wire the red/green onto the gG pair in the center, and the Yellow/Black onto the brown pair on the end - That way, the Ethernet can live hapily with the phone lines, and you won't be smoking the router with 70v ring voltage if somebody misplugs something. You can also use stock RJ-11(for the first line) and RJ45 cables without problems, and even run both down the same wire without repatch or pulling cable if you're cramped for plugs.
posted by Orb2069 at 12:30 PM on February 11, 2008

Response by poster: OK, can someone please 'plain what Orb2069 just said? Because the "smoking the router" part sounded kind of important.

I get that Ethernet is an 8-wire config and telephone is either 2- or 4-wire (usually 4), and I can theorize that it's important to have the wiring at any transition points be consistent, especially on both ends of the same cable. But how does the specific wiring pattern affect the voltage (70v ring voltage if somebody misplugs something)? And can I assume that if I go with some kind of pre-wired appliance (like this) that it isn't a concern?
posted by JParker at 4:44 PM on February 11, 2008

earthlink resells direct tv's sat. Internet service- and won't sell to you if you tell them you are playing video games or using voip. The latency can be more than .5 second, and they don't want the return.
posted by jenkinsEar at 5:04 PM on February 11, 2008

Response by poster: Another confirmation that satellite is going to be a problem for VoIP. Thanks jenkinsEar. I ordered DirecTV internet today. I will post my results back here.

After further thought, I think I understand some of Orb2069's comment, please correct if I am misunderstanding. Though both an IP phone network and the computer network can run over CAT6 cable, there are differing voltages involved which might cause problems. The logical thing to do would seem to me to be clearly identify phone jacks (e.g. use the blue plugs in the wall jacks for voice) and keep them separate in the wiring closet. One router for computer networking and one for phone.

But most VoIP is over existing computer networks. So there's clearly *not* a requirement to keep them separate. How does the wiring (bBoGgOrR to the 4-wire red/green and Yellow/Black) solve the voltage problem?
posted by JParker at 5:45 PM on February 11, 2008

If I'm reading Orb's comment correctly, he's suggesting using the unused pairs in a cat5 ethernet cable for carrying POTS service.

This way, you can combine both POTS (which is analog in your hours) and Ethernet- but if you mis-wire something, the ring voltage (which can be substantial) goes into your Ethernet network and not your phone. The ring voltage is so high because the old phones used to have mechanical bells that were rung by a small actuator in the phone. Good old days.

VOIP runs over TCP, but IP phones are expensive, so most folks use a gateway device to transform the VOIP signal into a POTS signal for your house, so they can use cheap phones (20 bucks versus 200 bucks a handset). If you don't have the 4-conductor twisted pair line run already in your house, you can follow ORB's strategy to leverage the unused pairs in your cat5.

I think it's academic anyway, as I still think VOIP over satellite will be miserable- might actually be better to get a broadband card from sprint or verizon and use that :)
posted by jenkinsEar at 6:20 AM on February 12, 2008

Check out the SPA-3000 from Sipura. They have FXS/FXO ports, with POTS fallback automatically built into the adapter.
posted by br4k3r at 12:22 PM on February 12, 2008

Yes, you can absolutely use the middle pair for POTS while you use the rest of the pairs for ethernet. You want to use T56B or T56A wiring standards to your RJ45 jacks. Depending on what you plug in at the wiring closet (POTS or ethernet switch), you make that jack behave however you want.
posted by Wild_Eep at 7:57 PM on February 12, 2008

Response by poster: Thanks for the additional info and clarifications. Seems to me that the higher voltage on phone lines creates the potential for crosstalk even if they're wired correctly, so, since I have some extra pairs of CAT6 in every room I'll keep the phone and data lines separate. KISS principal.

Thanks Wild_Eep for mentioning T56A/B, good to know.
posted by JParker at 10:20 AM on February 13, 2008

Came across this old thread just now ... Note that it's T568A and T568B. T568B is the more commonly used wiring standard. It's actually a tossup, as long as your consistent everywhere.
posted by intermod at 9:11 PM on August 31, 2008

« Older NOLA / Cool Food / Risky Hotel   |   Terms and Conditions. PDF OK? Newer »
This thread is closed to new comments.