Notification Service Technology

Question

I just checked Amazon SNS service (beta) to see how it works, but I became really confuse about the technology behind Notification Service. I am not looking for specific IOS or Objective-C answer, also I know it may use an open TCP connection (with an open port or long pooling), but I am looking for some information regarding the technology behind it or any possible protocols.

Please Let me know if you have any short reference for that.

Answer 1

SNS is about publishing notifications (pubsub).

Once you have a topic, you can create subscriptions. A subscription is roughly made by a protocol and an identifier (email, url).

Once set, topics will broadcast the messages to its subscribers

One of those, however, is SQS, which allows Long Polling (up to 60s).