Using Asterisk/FreePBX with a Comcast internet/phone line


I’ve just moved into a new apartment and I am building my home office from where I will work. I also want to hook up a few spare office phones I have and thought using FreePBX/Asterisk would be fun!

I’ve done some research and can’t seem to find the right advice, I wonder if this forums users can help Smile

What I currently have is a spare Dell optiplex which I am going to install FreeBSD onto and a Comcast internet/phone line that terminates in a Motorola VOIP cable modem. (Model number SBV5220)

I also have some phones, a Polycom SoundStation and two NEC DTH-8D-1 phones that were connected to our PBX at work.

So… I need to find out the answers to the following;

  1. Will this work? Can I connect up a cable from my Optiplex to the Comcast modem and have incoming calls routed to say one of the NEC’s and yet all the NEC’s and the Polycom make outgoing calls. Of course only one can create the outgoing call at any one time.

  2. What hardware am I going to need for the server? I’ve been reading Asterix’s hardware list but i’m a bit too fresh to this technology and some helpful pointers would be nice.

Thanks to those that respond.


if you’re really that new to asterisk, i’d recommend skipping freebsd and install trixbox, which is a version of centos (free red hat linux) with freepbx gui.

Okay, i’ll start reading up on that now.

Is what I am trying to do possible with the Comcast?

yes, i’m doing precisely that with my verizon landline. i misread your original post and thought you wanted to go straight VOIP. you’ll need an interface to your house wiring (FXS signalling) and an interface to the comcast NID (FXO signalling). the cheapest way would be to get a sipura SPA-3000 which runs $70 or so (if memory serves). it has one of each port. actually, to clarify, what are the phones you have? IP phones? if so, you don’t need the FXS port and could just get an X100P FXO PCI card for the dell to talk to the outside line.

Excellent! I have 4 phones in total. An old “Roseanne” phone in the kitchen, two NEC analog phones and an analog Polycom conference phone. So I think what I need is 3 or 4 ports which are FXS (I assume these are ordinary analog lines) and an FXO interface for the Comcast box?

do you really want them all being separate extensions? that could get expensive for the interfaces (a couple of hundred $$$).

Really? I was hoping these hardware cards had an extension per port. As in a 4 port card would let me connect 4 phones, each with a seperate internal extension.

I don’t need 4 lines coming into the house, I just want one line in and out, then have 3/4 phones in the house that can communicate with each other and also conference in 2 internal phones with one call from the outside line. I am planning on having a phone in my office, one down in the basement and use the existing old analog phone in the kitchen.

Am I being a little ambitious?

Oh and i’m willing to spend around $250 for the inteface cards…

oh you can do that no problem. get a digium tdm400 card with 1 fxo port (for comcast line) and 3 fxs ports (up to 3 inside lines). that’ll run you a couple of hundred tho, i think…

I could only find prices for $350+… where is the best place online to buy this stuff? … de=RTDM22B

those prices are pretty much it, i’m afraid. 4-port cards/adapters are not cheap. can you get ethernet to the locations of the phones? there is a nice gadget called an IAXy (i have one) that is a fxs/ethernet dongle. it is basically a teeny-tiny ATA that speaks IAX.

Actually if it is a lot cheaper I can get ethernet to any of the phones…

ATA? IAX? I still have a lot of reading to do :smile:

the IAXy runs about $80 or so. 3 of them is closer to your budget, i guess. plus $20 or so for the X100P to talk to comcast. IAX is an alternative to SIP.