How is traffic handled with interworx clustering?

Does the cluster manager handle all traffic communication with end users, both inbound and outbound?

So in that example traffic flow would be something like:
Internet -> CM -> Node -> CM -> Internet

Or, does the cluster manager handle all the inbound and the nodes take care of the outbound?

In that case traffic flow would be:
Internet -> CM -> Node -> Internet

The second scenario, Internet -> CM -> Node -> Internet, is how it works.