User mapping on FPN

dear experts,

I would loke to enable user mapping from a consumer portal ABC and a producer porta DEF

I already defined FPN, so I see DEF as producer of ABC.

I read from http://help.sap.com/saphelp_nw2004s/helpdata/en/43/2232900bb93fece10000000a11466f/content.htm

User Mapping in a Federated Portal Network

+In a federated portal network, user mapping can be used to create shortcuts between a user on the consumer and a system defined on a producer portal.+ User mapping cannot be used to map one user on a consumer portal to another user on a producer portalu2014the same user must be defined per individual throughout the network.

So, what is this ?

Have I to define a system on the producer that point to the consumer ?

Could you help me ?

Thanks.

Mario