The Net Services Topology Data Model stores the entire topological information about a single Oracle Application instance. The data model stores information about each node in the Oracle Applications instance which is then used to generate the Net Service configuration files (for example tnsnames.ora). AutoConfig seeds the data model with relevant data.

The Net Services Topology Data Model stores the following information:

* On the database tier: Hostname, Database SID, Database Name, Instance Name, TNS Descriptors.....
* On the application tier: Hostname, FNDFS and FNDSM alias descriptors.........

The Net Services Topology Data Model is seeded every time you run AutoConfig on the respective tier. Every time you run AutoConfig on the database tier, the relevant data is seeded/updated for the database tier. Respectively, every time you run AutoConfig on the application tier, the relevant data is seeded/updated for the application tier.