As part of my [VoIP adventure game]({{< relref "/ops/2020-01-20-voip-adventure-game.md" >}}), I need to set up a VoIP number, but thankfully my ISP ([iiNet](https://www.iinet.net.au/)) provides a free VoIP number to NBN customers, so that was covered. Next up I needed a virtual PBX, I went with [Asterisk](https://www.asterisk.org/get-started). This was an easy install on Ubuntu 18.04, just:

```
sudo apt install asterisk
```

Of course, installing software is much different from configuring it for use, so let me just preface this with describing some of my experience:

> AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH

Most of the frustration really just comes from getting my VoIP number registered. For iiNet users, there's some settings you can use [available on their website](https://iihelp.iinet.net.au/Setting_up_Netphone_%28VoIP%29). However be warned, getting them into Asterisk is slightly harder. You'll want to modify `/etc/asterisk/sip.conf` and add the following straight under your `[general]` line:

```
register => XXXXXXXXXX@iinetphone.iinet.net.au:YYYYYYYY:XXXXXXXXXX@iinetphone/XXXXXXXXXX
```

Make sure to replace the XXXXXXXXXX with your Netphone number (including state code) and the YYYYYYYY with your Netphone password.

Then at the bottom of `sip.conf` add the following:

```
[iinetphone]
host=sip.wa.iinet.net.au
fromdomain=iinetphone.iinet.net.au
fromuser=XXXXXXXXXX
username=XXXXXXXXXX
defaultuser=XXXXXXXXXX
context=inbound
disallow=all
;allow=g729
allow=ulaw
allow=alaw
insecure=port,invite
canreinvite=no
secret=YYYYYYYY
type=friend
nat=yes
qualify=yes
```

Make the same replacements, but also change `sip.wa.iinet.net.au`, replacing the state (second section) with your home state.

Now open up `/etc/asterisk/extensions.conf` and find the section labelled `[default]` and change it to the following:

```
[default]
include => inbound
```

Then append the following to the end of the file:

```
[inbound]
exten => XXXXXXXXXX,1,Answer()
exten => XXXXXXXXXX,1,Wait(5)
```

Replace XXXXXXXXXX with your Netphone number once more.

Make sure you restart Asterisk (`systemctl restart asterisk.service`) and you should be able to call the number. Expect it to answer, wait 5 seconds, then immediately disconnect.

Now you can do whatever you want to configure it to answer, send to a softphone extension or a VoIP handset, etc.