well managed to sort out my issue of secondary extensions not ringing on incoming calls though have hit another stumbling block when trying to get ilbc codec working
can call out quite fine with my provider Mynetfone here in australia using ilbc though incoming calls using this codec turn to garbage with no recognizable audio, I also get this logged on the incoming call: "An ilbc frame that isn't a multiple of 50 bytes long from RTP (38)"
I thought it must be an rtp frame size issue with the provider possibly using 40ms instead of 30ms, though another Mynetfone user reports it working?
see here:
http://forums.whirlpool.net.au/forum-replies.cfm?t=974927&p=2#r22 
