Jabber iPhone TCT in CUCM 9+ only

[Jason Aarons]

APN is a cloud push for IM from what I read, not doing IM but Jabber for iPhone with Phone Only with CUCM 11.5.1SU4. On premise only, no cloud access. Is APN required for iPhone in background with Phone Only?

[Jaime Valencia]

No, that understanding is wrong.

APNS was actually delivered in two phases by Cisco, first IM (SU2), and then voice (SU3).

APNS is used by any app that goes to the background and needs to receive a notification.

[Jason Aarons]

So for on-premise voice only, can't use Apple iPhone connected to WiFi. Apple requires Internet at all times to run in background for voice only.

[Jaime Valencia]

Yes, the device needs to have internet connectivity at all times to get the notification from the APNS cloud.

https://faq.whatsapp.com/en/iphone/20950116/

https://support.apple.com/en-us/HT203609