问题
Sometimes I am experiecing a delay while receiving APN , while at other times its working absolutely fine.
I am also connecting to the feedback server at ssl://feedback.sandbox.push.apple.com , but its not showing any data.
What are the possible reasons for the delay?
Thanks
回答1:
Delay can happen if you've got a bad connection on 3G or Edge (iPhones use those, not wifi, for push unless they're totally unavailable). If the connection is dropped but the device doesn't know it, it'll wait until it does a heartbeat and realizes the connection is closed.
Also, if you're using an iPod Touch, the connection to the push servers will only be maintained while the backlight is on or you're plugged in via USB; otherwise the wifi connection will be dropped when the backlight goes off to save power, and it'll poll for new notifications every half an hour.
来源：https://stackoverflow.com/questions/1807456/delay-in-receiving-apn-on-iphone