I’ve spent most of the afternoon installing Asterisk at Home 2.8.Â Why?Â Because I’ve never installed Asterisk before, I wanted to know what the experience would be like, and I have been inspired for some months by Ward Mundy’s Nerd Vittles blog.Â Ward has dozens of neat projects that you can build with Asterisk, and it just looks fun!
I bought the cheapest PC I could find for this project.Â Staples is selling off a 3 Ghz Compaq unit with 512M of memory and a 100G drive for under $400.Â I also went cheap on the FXO / FXS interfaces — I found a $15 FXO in Hong Kong from a company called X100P.Â They came with no documentation.Â I bought the analog interfaces despite the fact that they’re not required for straight IP telephony, because I want to try interfacing this into my home phones.
Installation is pretty simple.Â Download the ISO image, burn it, stick it in the PC, and reboot.Â Answer aÂ couple of questions, andÂ an hour or so later, you have a PC with Asterisk up and running.Â No futzing around with different packages, and other stuff.Â It’s all there for you.
And this is where the fun starts.
The first thing, once you’ve installed, is to go and get the latest CentOS updates.Â There were 32 updated packages.Â Then, because there were kernel changes, I had to rebuild the Zaptel drivers (ZaptelÂ boards areÂ the analog boards built and sold by Digium.Â The cheap one I bought was a clone of a Digium FXOÂ board).Â I also had to download a patch to spinlock.h, because the standard one breaks the Zaptel build.
When that was done I ran into the first substantial hurdle.Â CentOS couldn’t see my FXO card. I read and read a couple of enormous threads on this, but to no avail.Â Eventually, I opened the PC, and pulled out the modem that shipped with it, wondering if there might be some kind of conflict between it and the FXO card.Â On reboot, there wasÂ my FXO!Â Phew.
Next job was to configure some extensions.Â A couple of softphones, and the x100PC.com s100 FXS.Â The s100 was tricky.Â I figured out with some reading, and visiting VoIP-INFO.ORG that it comes configured with a static IP address on a different subnet from the one I use at home.Â Luckily, there was a s100 manual on VoIP Info, otherwise I would have been lost.Â The s100’s english language directions are not super clear, and some of the defaults it uses are unintuitive.Â Â Still, it speaks IAX, which makes it a good choice for Asterisk.
I also configured a Virbiage Cubix softphone, the only softphone I’ve seen yet that can speak IAX.Â It’s simple andÂ seems fairly robust.
At this point, I was able to pass calls back and forth between devices on my network, but not yet call out.
My strategy for configuring the call out is to first configure it with a SIP provider, and then configure the FXO card.Â My thinking is that if it takes a while, I will be forever disconnecting the family phone from the network, which is not a good thing.Â Â Without too much difficulty, I was able to get my SIPPhone account configured, and now have Asterisk registering.Â And, in fact, I can send dialing digits to SIPPhone, but I cannot yet dial out. Every time, it comes back and tells me the user I am trying to reach is unknown.Â I suspect I have simply made an error in the dialing plan.Â More reading is required.
Dinner, at this point, beckoned.Â By the end of the week, though, when I have some spare time, I expect to have this all configured and up and running.