Till now there is no available manual how to upgrade directly form older versions of Kamailio to actual version of 4.0. Therefore we will upgrade with a middle step, first we upgrade from 3.2 to 3.3, and then from 3.3 to 3.4. Migration from 3.2 to Kamailio 3.3 and then to 4.0 requires upgrade of installed packages, database structures and configuration file.
Upgrade of Packages
First, we have to add correct debian repository of kamailio version 3.3. So open your apt source list file
and add for ''Debian Squeeze''
deb http://deb.kamailio.org/kamailio33 squeeze main deb-src http://deb.kamailio.org/kamailio33 squeeze main
and we have to update the debian packages list
apt-cache show kamailio
we should see available different versions of kamailio packages.
After update we can start main upgrade