Asterisk Add-On Package
From ImageStream Router Documentation
From the command line type the following:
Then reboot the router. When the router comes up go back to the command line:
addon_hd configure addon_hd format Enable addon_hd Install asterisk Enable asterisk Start asterisk backup flash
Access the Asterisk web admin via: http://192.168.0.1:8080/asterisk/static/config/cfgbasic.html
Change the IP to the IP of your router.
The asterisk configs are stored in /etc/asterisk which is on the ramdisk just like all other router settings.
Any changes that are made to the asterisk configs will need to be saved to flash using the "backup flash" command or the save configuration to flash menu option.