Creating a basic Asterisk Training Setup

I’m putting together a super basic PBX setup to train people on. It has very basic SIP peering to gain access to the PSTN, and a basic dialplan that maps a few users to extensions (when ringing times out, they go to voicemail). I’ve also included a feature code for accessing vmail.

Additionally, I have a very basic setup for configuing a Digium FXO card, as well as the DAHDI config stuff (system.conf/modules/chan_dahdi.conf).

It covers all the really basic stuff of a simple PBX. I’m going to add a second PBX and setup some IAX peering between them to cover that as well. Besides this, what other stuff would anyone recommend to add? The goal is to show someone how to setup basic PBXs to sell to small offices. Included below are links to the various configs.

Main dialplan and peering:
http://pastebin.com/xrrEDPrg

Analog/DAHDI stuff:
http://pastebin.com/9ZNhYV8R