Does the Apple Push Notification Service represent

Question

I've been reading up extensively on APNS, and was curious if anyone is familiar with Apple's stance on server-side logging. In order to allow for push notifications, each device (such as an iPhone) "establishes an accredited and encrypted IP connection with the service and receives notifications over this persistent connection."

Source: https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/ApplePushService.html

This essentially means that Apple tracks every single IP address that a user's phone is connected to at any time including wifi hotspots, and will initiate an automatic connection with its servers when the user enters his/her own home, even when that user is not actually using his/her phone. While I understand this process is essential to allowing for push based notifications, my question is for how long does Apple keep this log data?

(They claim to not log the content of notifications including iMessage here: http://images.apple.com/ipad/business/docs/iOS_Security_Feb14.pdf However, I'm interested in the logging of the metadata associated with those notifications.)