Subject: Re: Internet telephony. (In Turnette, tell a phony?)
To: Richard Rauch <>
From: Andrew Gillham <>
List: netbsd-users
Date: 03/26/2005 22:48:47
On Fri, 25 Mar 2005 04:06:15 -0600, Richard Rauch <> wrote:
> Okay.  Thanks.  I'll take you up on that; here are a few offhand:
>  * If I ever want (or for some reason need) a traditional phone,
>    what would I be looking at by way of hardware to add to the
>    computer?  (I am familiar with none of this...)

If you mean a phone handset you need an "FXS" port (Foreign eXchange
Station), if you mean the line from the CO, you need "FXO" (Foreign
eXchange Office) ports.

You can buy something like the standalone Sipura SPA-3000 (Has 1 FXS,
1 FXO, 1 Ethernet) so you don't need to install anything in your PC.

For a real piece of hardware in your PC you need a Digium TDM400P.
With one port (FXS or FXO) it is ~$130.  With one FXO & one FXS it is $195.

Jeff ported the driver to NetBSD for the TDM400P so it should be working well.
>  * What kind of CPU would be required?  My fastest system should be
>    more than sufficient (AMD64), but every 15 seconds or so it seems
>    to have a system-wide freeze for a second (this started around August,
>    last year, give or take, and persists with a 3.99.1 kernel that I
>    built a couple of days ago).  The next fastest computer that is
>    directly on the 'net is an old 450MHz (I think) Pentium III.
>    (Inbetween, I have an 800MHz Athlon that is off of the 'net...
>    I thought that I read something about NAT causing problems for
>    this, though, and that computer is not likely to be put directly
>    on the 'net.))

The "freezing" issue sounds deadly for voice.  If it blocks the PBX
your calls will not work.

I think a 450Mhz P3 should be more than sufficient for a few
concurrent calls.  I was using a Duron 600 (running Debian) in the
past and it was pretty much idling even with a few calls going on.

I also experimented with asterisk on a PII 400mhz running NetBSD.  It
worked for my tests, but it was in the early days of BSD support so
had various issues that made it unusable.

NAT works ok on Asterisk if you public isn't changing.  Of course
having a public is much better. :)