The Replication Server gateway supports cascading connections, which allow your Replication Server to communicate with servers it is not directly connected to.
Cascading connections also allow you to manage a replication domain using a single client connection. For example, you can connect to an ID Server, and then to the ID Server’s RSSD. In this case, both the primary, controlling Replication Server and the ID Server are gateways; commands pass through to the ID Server’s RSSD, and result sets pass back through to you.