First, let’s see if there is some misunderstanding of what Akka Cluster does. The core of Akka Cluster is “only” cluster membership, to keep track of what nodes are part of the cluster and their health. Then there are various tools built on top of the cluster membership, such as Distributed Data or Cluster Sharding.
What information exchange? The cluster membership? The messages that some of the specific tools are sending, which tool then? Other exchange would be your own messages and then it’s up to you to decide where to send those messages.
I don’t think Akka Cluster is suited for a public peer-to-peer application over the internet. The purpose of Akka Cluster is to have a few (100) nodes tightly connected that together implement a service or application. Communication with other systems should be done with other protocols, such as HTTP, gRPC, message broker.