I’m Philipp, an IT Systems Engineer from Potsdam, Germany and want to deepen my knowledge in SIP communication on scale.

Currently, my setup is quite simple: A single stateless Asterisk instance, fully managed via ARI, which registers to multiple VoIP providers, only processes incoming calls to play audio files (no outgoing or conference calls).

Now, with growing load on the single Asterisk instance, I would like to have one or two Kamailio instances, which will balance the load of incoming calls to multiple Asterisk instances. On which Asterisk instance they end up is irrelevant for me, as the calls can be processed on every instance.

I looked into some Kamailio and Astricon conference speeches and checked out some tutorials. But still I’m not quite sure where to start. So here are some basic questions which would really help me out to get going:

• As I don’t want to have registrations of all my Asterisk instances at the VoIP providers, I should use the UAC module to let Kamailio do the registering to the VoIP providers and register my Asterisk instances to Kamailio, right?
• Will Kamailio automatically apply new outbound registrations when added to the database or do I have to trigger that manually?
• Should I use one or two instances of Kamailio, how hard is it to configure them fail-safe?
• For writing my first config file, should I start blank or from the standard config, what’s best practice?