What features does my server need for Apple push notifications?

I'm developing an app that makes use of the Apple Push Notification Service.

I'm looking for hosting of the server side. What features do I need to implement the service properly开发者_运维技巧?

Thanks :)

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How to build an Apple Push Notification provider server provides a great guide for getting started with APN.

Depending on how many APNs you need to send you may want to check out Urban Airship. You can send up to 1 million messages a month for free with their service.