Ports required for Apple Push Notification Service

We encountered a problem where Macs managed by Casper were unable to communicate with the JSS for Mobile Device Management (MDM).  The solution was to allow the following ports access to Apple's 17.0.0.0/8 range (complete owned by Apple):

• TCP port 5223 (used by devices to communicate to the APNs servers) 
• TCP port 2195 (used to send notifications to the APNs)
• TCP port 2196 (used by the APNs feedback service)
• TCP Port 443 (used as a fallback on Wi-fi only, when devices are unable to communicate to APNs on port 5223)

Here is a link to Apple's support page on the topic.