I've done more testing on this and have established the following test case:
Test 1
iPhone with wifi off and cellular connection on.
Push works.
Uunplug sim card to kill cellular connection
Turn on wifi
Push works
Test 2
iPhone with wifi off and cellular connection on
Push works.
Turn on wifi
Push fails.
In case 1, the sync.log shows that the IP address of the handset changes from the public IP provided by the cellular carrier, to the internal IP provided by our own DHCP server. As a result of the server knowing where the phone is, push continues to work.
In case 2, the server log file shows the public IP address still for the phone, and does not change to the internal IP address.
Now, that would seem to be an issue with the iPhone, rather than the zimbra server, but there is a third case, that of the phone switching between wifi and cellular connecitons while on a lan other than the one local to the zimbra server, such as me being at home and using both my wifi and the cellular network as I walk in and out range; this works fine, push continues to work in this condition.
Could some other people investigate to see if you can replicate these results? This problem means that push does not work for the staff while they are on site.  |