Oracle Database Discussions

Hi,

I need some help understanding the following source routing function of Connection Manager. The book says:

"Source routing is used with Connection Manager. CM servers as a proxy server for Oracle Net traffic, enabling Oracle Net traffic to be routed securely though a firewall. Oracle Net treats the addresses as a list of relays, connecting to the first address that then requesting to be passed from the first to the second until the destination is reached. It differs from failover and load balancing in that all addresses are used each time a connection is made".

I do understand it is possible to configure CM in such a way that it can act as a firewall, accepting and rejecting connections based on certain criteria. What I do not understand is the second part where the addresses are treated as a list of relays. Why would something like this be necessary and how could that be configured in CM.

Any help would be greatly appreciated....

Thanks in advance.