[OpenSIPS-Users] Push notifications to users

[Carlo Dimaggio]

Hello all!

I'm thinking about a nice service in order to send a push notification  
to users when there is, for example, a missed call (when the device is  
not logged in) or a new message in the voicemail (like the iphone  
skype/facebook notification).
Do you have any experience on this? Could you share any useful link?
I would like to know what protocols, technologies should be involved  
in this process.

Thank you.


Best Regards,
Carlo Dimaggio