What is the overall data flow for the Subscription process

I am trying to build a Windows service that can collect call-log data from the RingCentral system, as real-time as possible. I am working in .NET Visual Basic. I have been able to POST requests to the RingCentral URL and get responses. I have also created a PubNub account and can Publish and Subscribe just fine. I understand that at RingCentral, I am supposed to POST a Subscription request and get my DeliveryMode Address and SubscriptionKey. I can see how they can be integrated with the PubNub URL. In one of the PubNub examples, I was able to Publish a string and subsequently Subscribe to the Channel and retrieve the string. What I am trying to understand is how do I access the new RingCentral notifications? Do I have to keep checking the PubNub URL for new data? Is PubNub the data host and that is why I have to query PubNub and not RingCentral directly? I don't have a data stream to test against, so when I Subscribe to PubNub I get nothing significant back. I might be on the right track and just lacking live data. Within our product, we use Marshalling so I know right away when there is new data. This process here, seems like I have to continuously query PubNub checking for new data. Is that correct?