Apple's APNS Delivery is Sometimes Slow

Question

Using our own inbuilt APNS push system (written in PHP), we push to our devices on certain events. Some notifications are received by devices fairly instantaneously, while

Answer 1

Going on some previous information in other threads, it appears that it may not be 'uncommon' if a delay occurs.

While in most cases you should expect a delivery in seconds, apparently it can be up to 30 minutes, just due to networking issues such as mobile network drop-outs and other factors.

Source: How much delay of ios push notification? and also: Apple's APNS Docs