[gsich]

I am not sure why maintaining a TCP connection to Google or Apple is somewhat more battery friendly then maintaining it to your own server, or providing a TCP-server to provide some service for someone else. (UDP is different here)

I am using CSipSimple to my own server, battery usage is the same. Yes this is anecdotal evidence, but one can always check.

[tomaskafka]

I guess this changes the moment you have 100 apps, each doing 'just a quick ping to my server time to time'.

Unfortunate result is hundred of apps waking up the phone ever 20 seconds and transmitting data nonstop. Sigh.