Help with setting up Asterisk in a small office


I am new to Asterisk, and am working my way through the Asterisk book, but I had some questions that I was hoping to bounce of the Asterisk gurus on this forum.

I’m trying to set up Asterisk for a small office setup, which has Time Warner Digital phone service - which means we have a modem that gives us 2 POTS lines.

So my plan is

  1. Buy and install an FXO card (like a TDM402B) on the desktop, to connect the phone lines coming out of the Time Warner modem.
  2. Install AsteriskNOW on a fairly competent desktop
  3. Connect the computer to a router, that is connected to the company’s wired network
  4. Each office has a LAN port, and I can hook up a SIP phone (like the Digium D40) to each port.
  5. Make a customized Dialplan - (I have a lot to read about here, and there is lots of info the Asterisk book)

I was wondering if this sounds like a good plan? Can I save on hardware/software costs in any way? Can I hook up Time Warner’s modem directly to the desktop without having to get an FXO card?

Any suggestions from this forum is most welcome.


I dont think you can hook up Time Warner’s modem directly to the desktop without FXO card. The modem is used to convert the analog signal out for your regular phone.
However, I think you can ask your service provider to give you the “SIP account” so you dont need to use the ATA modem or FXO card, all you need is the Internet connection of the desktop computer that installed AsteriskNOW. You setup your VoIP as SIP trunk in AsteriskNOW.

TieUs Technology, Canada SIP Trunk


I was wondering if someone could help me with a problem I’m having - I have bought and setup the hardware as described in the first post, installed AsteriskNOW, and made a couple of SIP extensions for the 2 D40 phones.

When I try to make an internal call from one SIP phone to another, I just dial the extension and everything works OK.

I have also set up a DAHDi trunk, and an outgoing route to connect to that trunk. However, when I try to make an outside call from one of the extensions, I get a recorded message saying “Your call cannot be completed as dialed”.

Can someone please help???

P.S. The hardware is recognized by Asterisk, as evidenced by the glowing lights at the back of the card.

Digium’s Support department can assist with troubleshooting the card, if you like: