Working largely on his own, Kristian has gone to great lengths to get the combination of the OS and Asterisk down to a mere 26 MB boot image. This opens up many possibilities in the design of the hardware, such as booting from small compact flash cards or USB memory keys.
While keeping the size of the system to a minimum, Astlinux includes the following features:
- Linux kernel 22.214.171.124
- watchdog (busybox)
- cron (busybox)
- busybox (and everything with it...)
- TFTP server
- vsftpd server
- mini_httpd (with SSL)
- PHP in CGI mode (patched for above)
- NTP (ntpdate, ntpq, ntpd)
- syslog (busybox with remote log support)
- vi (from busybox)
- tc (kernel traffic shaping)
- phpconfig-like Asterisk GUI
- AstShape, a QoS/traffic shaping script
- nfs-utils (kernel modules and userspace tools for NFS support)
- Sangoma WanPIPE driver use with Sangoma T-1 hardware
- Zaptel drivers for Digium TDM hardware
- working ztdummy (zaptel timing source without zaptel hardware)
- Asterisk Manager Proxy
Don't be too worried if some of these don't mean anything to you. Astlinux is focused on providing only those things in the OS that are necessary to support the normal operation and administration of Asterisk. For example, email support is provided so that voicemail messages can be forwarded via email like any normal Asterisk installation. The inclusion of ztdummy allows for both MeetMe conferencing and music-on-hold, without requiring a Digium card for a hardware timebase reference.
While the list of required supporting services may appear long, the idea is very simple - create a very small Linux and Asterisk installation that supports common telephony hardware, and once configured, behaves like an appliance.