Asterisk in container with Debian stable

Asterisk is free and open source code to create software PBX server. See [1] for details. This package perfectly runs in side OpenVZ container. Some users run up to 60 containers with Asterisk deployed for production per single hardware node. Although the easiest way to install Asterisk into container is to use pre-build package from Linux distribution, occasionally one may need to have a possibility to build it from source tarball available on developer's site.

In order to do it the following remarks are worth reading:

Asterisk PBX server itself is compiled out of the shelf in CT provided that develop application template is installed for this CT. The functionality of the resulting executable is enough to support simple VoIP telephony.

Unfortunately, one particular module called MeetMe (conferencing tool) will be switched off from compilation. This happens due to external dependency on 'zaptel' package. This package provides support for some hardware cards for FXO/FXS analog telephony marketed by Digium (the company behind Asterisk), and on top of that supplies so called ztdummy kernel module. Ztdummy works like a simple metronome which is required to synchronize multiple sound streams in case of conference call. Initially this module requires 1 kHz clock which is avail for example on all Digium cards.

If you do not have this card (or equivalent from other vendors) as in case if you do not plan to use analog telephone lines, nothing is lost. You just need to play a little trick with Asterisk make system and HN ovz kernel. First one needs to download zaptel tarball from the same location as Asterisk itself, and copy it's header zaptel.h to location /usr/include/zaptel/zaptel.h in the CT where you plan to build Asterisk. This tweaks MeetMe for installation. Then you need to build ztdummy.ko in HN and make it auto-loaded.

Below is an example of how to install Asterisk into OpenVZ VE based on debian stable aka. "sarge":

$ apt-get install asterisk

$ nano /etc/defaults/asterisk

change:

RUNASTERISK=no -> yes
AST_REALTIME=yes -> no (for realtime, you need

$ /etc/init.d/asterisk start

modify the config files for asterisk, and done!

if you need capi or/and zaptel/zaphfc:

• for capi: you need the /dev files on you hw-node and vps:

crw-rw---- 1 root dialout 68, 0 Jan 3 2006 /dev/capi20
crw-rw---- 1 root dialout 68, 1 Jan 3 2006 /dev/capi20.00
crw-rw---- 1 root dialout 68, 2 Jan 3 2006 /dev/capi20.01
crw-rw---- 1 root dialout 68, 3 Jan 3 2006 /dev/capi20.02
[...]

/* if the files doesn' exist use mknod for creating it*/

and in your vps config add for directly access:

DEVICES="c:68:0:rw, c:68:1:rw, c:68:2:rw"

• for zaptel/zaphfc:

crw-rw---- 1 root dialout 196, 0 Jan 4 2006 ctl
crw-rw---- 1 root dialout 196, 1 Jan 4 2006 1
crw-rw---- 1 root dialout 196, 2 Jan 4 2006 2
crw-rw---- 1 root dialout 196, 3 Jan 4 2006 3
crw-rw---- 1 root dialout 196, 4 Jan 4 2006 4
[...]
crw-rw---- 1 root dialout 196, 253 Jan 4 2006 timer
crw-rw---- 1 root dialout 196, 255 Jan 4 2006 pseudo
crw-rw---- 1 root dialout 196, 254 Jan 4 2006 channel

/* if the files doesn' exist use mknod for creating it*/

and in your vps config

DEVICES="c:196:0:rw, c:196:2:rw, c:196:1:rw, c:196:253:rw,c:196:254:rw,c:196:255:rw"

if need both (capi and zaphfc)

DEVICES="c:68:0:rw, c:68:1:rw, c:68:2:rw c:196:0:rw, c:196:2:rw, c:196:1:rw, c:196:253:rw,c:196:254:rw,c:196:255:rw"